# Truck Ins. Exchange v. Kaiser Cement & Gypsum Corp.

> California Supreme Court · June 17, 2024

URL: https://www.frixlaw.com/law-library/cases/10034059

## Case

- **Court:** California Supreme Court
- **Decided:** June 17, 2024
- **Precedential status:** Published
- **Opinion:** Opinion
- **Cited by:** 0 later opinions in the Frix Law Library

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## Opinion text

IN THE SUPREME COURT OF
CALIFORNIA

TRUCK INSURANCE EXCHANGE,
Plaintiff and Appellant,
v.
KAISER CEMENT AND GYPSUM CORP. et al.,
Defendants, Cross-complainants and Appellants;
LONDON MARKET INSURERS,
Defendant and Appellant;
INSURANCE COMPANY OF THE STATE OF PENNSYLVANIA,
Cross-defendant and Appellant;
GRANITE STATE INSURANCE COMPANY et al.,
Defendants and Respondents.

S273179

Second Appellate District, Division Four
B278091

Los Angeles County Superior Court
BC249550

June 17, 2024

Justice Groban authored the opinion of the Court, in which
Chief Justice Guerrero and Justices Corrigan, Liu, Kruger,
Jenkins, and Evans concurred.
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
S273179

Opinion of the Court by Groban, J.

This appeal requires us to decide when a first-level excess
insurer’s indemnity obligations attach in the context of a
continuous injury that triggers multiple policy periods. In
Montrose Chemical Corp. of California v. Superior Court (2020)
9 Cal.5th 215 (Montrose III),1 we addressed the sequence in
which an insured could access its excess insurance policies for
continuous environmental damage that had occurred over two
decades. The insured sought a rule of “vertical exhaustion,”
which would allow it to access an excess insurance policy as soon
as all the directly underlying insurance from that policy period
(i.e., any primary and any excess policies with a lower
attachment point) were exhausted. (See id. at p. 225.) The
insurer sought a rule of “horizontal exhaustion,” which would
not allow the insured to access an excess policy until it had
exhausted every excess policy with a lower attachment point
across all relevant policy periods. (See ibid.) The parties to
Montrose III did not dispute that all primary policies had been
exhausted. Thus, the only issue before us was whether, upon
exhaustion of all primary policies, the availability of excess

1
Because Montrose Chemical Corp. of California v.
Superior Court (2020) 9 Cal.5th 215, is the third and most recent
decision in a series of cases involving the Montrose litigation,
the Court of Appeal and the parties refer to it as “Montrose III.”
We will use the same short form here.

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

policies was governed by a rule of vertical or horizontal
exhaustion. (See id. at p. 226, fn. 4 [“Because the question is not
presented here, we do not decide when or whether an insured
may access excess policies before all primary insurance covering
all relevant policy periods has been exhausted”].)
This case requires us to resolve the question that we left
open in Montrose III: whether standard language in commercial
general liability policies that are excess to primary insurance
policies should be interpreted to require vertical or horizontal
exhaustion. In other words, can an insured access a first-level
excess insurance policy upon exhaustion of underlying primary
insurance obtained for the same policy period (vertical
exhaustion), or is the insured required to exhaust all primary
policies issued during the continuous period of damage
(horizontal exhaustion)?
The appellant in this case is Truck Insurance Exchange
(Truck), a primary insurer for Kaiser Cement and Gypsum
Corporation (Kaiser). Truck filed an equitable contribution
claim against several insurers that had issued first-level excess
policies to Kaiser for policy years where the directly underlying
primary policy had been exhausted. Relying on our reasoning
in Montrose III, supra, 9 Cal.5th 215, Truck argued that the
excess insurers’ indemnity obligations were triggered
immediately upon exhaustion of the directly underlying primary
policies. Truck further reasoned that because the excess
insurers owed a coverage duty to Kaiser, they were effectively
responsible for indemnifying the same loss as Truck and should
therefore be required to contribute to Truck’s coverage costs.
The excess insurers, however, argued that they had no duty to
indemnify Kaiser until it had exhausted every primary policy

2
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

issued during the period of continuous damage (including the
policy Truck had issued), and thus there was no possible basis
for contribution. According to the excess insurers, Montrose III’s
analysis is limited to excess policies that sit over other excess
policies, not first-level excess policies that sit over primary
insurance. The Court of Appeal agreed that Montrose III did not
extend to excess policies that sit over primary insurance, which
has characteristics that are distinct from excess insurance
including immediate coverage and defense obligations. In so
ruling, the court rejected SantaFe Braun, Inc. v. Insurance Co.
of North America (2020) 52 Cal.App.5th 19 (SantaFe), which
held that Montrose III’s reasoning does apply in the context of
first-level excess policies. The court further concluded that
because the excess insurers had no coverage obligation under
their policies until all primary insurance had been exhausted
(including Truck’s primary policy), Truck was not entitled to
contribution.
Contrary to the Court of Appeal, we conclude that our
analysis in Montrose III applies equally here. The language of
the first-level excess policies at issue in this case is essentially
identical — and in some cases actually identical — to the policy
language in the higher-level excess policies that we considered
in Montrose III. The policies also share many of the same
characteristics that we found “strongly suggest[ive]” (Montrose
III, supra, 9 Cal.5th at p. 233) of vertical, rather than
horizontal, exhaustion. Thus, as in Montrose III, we believe the
first-level excess policies are most reasonably construed as
requiring only vertical exhaustion.
The excess insurers seem to concede — or at least do little
to dispute — that the language of their policies is substantially

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

identical to the policies at issue in Montrose III. They argue,
however, that such language should be assigned a different
meaning in the current context given the “qualitative
distinctions” between primary and excess insurance.
Specifically, they note that primary insurers generally receive
higher premiums and offer lower liability limits in exchange for
coverage that attaches immediately upon the happening of an
insurable occurrence and provide defense costs. We are not
persuaded that those distinctions justify adopting a different
interpretation of the exact same policy language that we
construed in Montrose III.
Our conclusion that the first-level excess policies only
require vertical exhaustion does not, however, fully resolve the
questions presented in this appeal. Unlike in Montrose III,
which involved an insurance coverage dispute between an
insured and its insurer, this case involves a contribution claim
between coinsurers. While coverage disputes between insureds
and their insurers are a form of contract action that turns on the
meaning of the policy language, “an equitable contribution claim
between coinsurers is not based upon contract, but instead
involves ‘ “equitable principles designed to accomplish ultimate
justice in the bearing of a specific burden.” ’ ” (Axis Surplus Ins.
Co. v. Glencoe Ins. Ltd. (2012) 204 Cal.App.4th 1214, 1227–1228
(Axis), quoting Signal Companies, Inc. v. Harbor Ins. Co. (1980)
27 Cal.3d 359, 369 (Signal).) Although the terms of the relevant
policies are an important factor when deciding whether
contribution is appropriate, courts may consider “a variety of
[other] factors” (Travelers Casualty & Surety Co. v. Century
Surety Co. (2004) 118 Cal.App.4th 1156, 1162), including “ ‘ “the
nature of the claim, the relation of the insured to the insurers

4
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

. . . and any other equitable considerations.” ’ ” (Truck Ins.
Exchange v. Unigard Ins. Co. (2000) 79 Cal.App.4th 966, 974
(Unigard); see Signal, at p. 369.) Thus, our finding that the
first-level excess policies do not require the insured to
horizontally exhaust primary insurance issued during different
policy periods does not resolve whether Truck is entitled to
contribution from the excess insurers.
In the proceedings below, the excess insurers and Kaiser
argued that even if the policy agreements were, as a matter of
contract interpretation, properly construed as authorizing the
insured (Kaiser) to access its first-level excess insurance upon
exhaustion of the directly underlying primary insurance, it
would nonetheless remain unfair as a matter of equity to allow
a primary insurer to obtain contribution from an excess insurer
given the distinct roles those two types of carriers play in
covering a loss. (See generally Dart Industries, Inc. v.
Commercial Union Ins. Co. (2002) 28 Cal.4th 1059, 1080 (Dart)
[“the obligation of successive primary insurers to cover a
continuously manifesting injury is a separate issue from the
obligations of the insurers to each other”].) They further
contended that ordering contribution would be particularly
unfair under the specific circumstances of this case because it
would effectively allow Truck to pay less insurance than it had
promised to Kaiser, while leaving Kaiser and injured asbestos
claimants with less overall coverage.
Because the Court of Appeal rejected Truck’s contribution
claim based entirely on its erroneous interpretation of the excess
policies (i.e., that the excess insurers had no coverable obligation
under the policies until Kaiser horizontally exhausted all
primary insurance), it did not reach these alternative

5
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

arguments regarding the fairness of ordering the excess
insurers to contribute to Truck. Having now concluded that the
excess policies require only vertical exhaustion, we remand the
matter to allow the Court of Appeal to address these alternative
arguments in the first instance. (See Hamilton v. Asbestos Corp.
(2000) 22 Cal.4th 1127, 1149 (Hamilton) [“It is appropriate to
remand for the Court of Appeal to resolve . . . in the first
instance” issues that the court chose “not [to] reach because of
its holdings”].)
I. BACKGROUND
From 1944 through the 1970s, Kaiser manufactured
asbestos-containing products at numerous different facilities.
By 2004, more than 24,000 claimants had filed product liability
suits against Kaiser alleging that they had suffered bodily
injury (primarily asbestosis or cancer) as a result of exposure to
Kaiser’s asbestos products. (See London Market Insurers v.
Superior Court (2007) 146 Cal.App.4th 648, 652.) Kaiser
tendered these claims to Truck, one of several primary insurers
that had issued commercial general liability (CGL) policies to
Kaiser during the relevant time period.
In 2001, Truck initiated this insurance coverage action to
determine its indemnity and defense obligations to Kaiser.
Several years later, Truck amended its complaint to add a cause
of action for contribution against several of Kaiser’s excess
insurers. The litigation has generated multiple appellate
decisions that have addressed a wide range of complex questions
regarding insurance coverage and policy interpretation. In this
appeal, we review only one of the issues decided by the Court of
Appeal: Whether Truck is entitled to contribution from various

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

coinsurers that issued first-level excess policies to Kaiser during
the period in question.
A. The All Sums with Stacking Approach to
Continuous Injuries
Before turning to the procedural history of the parties’
current dispute, it is helpful to review general principles of
insurance law that govern “continuous or ‘long-tail’ injury . . .,
where damage occurs over multiple policy periods.” (Montrose
III, supra, 9 Cal.5th at pp. 226–227.) In the context of standard
“occurrence based” CGL insurance policies,2 California has
adopted what is known as the “all-sums-with-stacking”
approach to continuous injuries. This approach has three
primary components. First, in Montrose I, supra, 10 Cal.4th
645, we adopted the “continuous injury trigger of coverage”
principle (id. at p. 685), under which “bodily injury and property
damage that is continuous or progressively deteriorating
throughout several policy periods is potentially covered by all
policies in effect during those periods.” (Id. at p. 655.) In other

2
While the specifics of their language may vary, traditional
“occurrence based” CGL policies generally insure the
policyholder for “ ‘all sums which the insured shall become
legally obligated to pay as damages because of . . . bodily injury,
or . . . property damage to which this insurance applies, caused
by an occurrence.’ ” (Montrose Chemical Corp. v. Admiral Ins.
Co. (1995) 10 Cal.4th 645, 656 (Montrose I); see id. at pp. 669–
670 [discussing drafting history of standardized CGL policy
language].)

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

words, the insured may call upon any policy that was in effect
during the continuous period of injury.3
Second, in Aerojet-General Corp. v. Transport Indemnity
Co. (1997) 17 Cal.4th 38, we adopted “the ‘all sums’ rule” (State
of California v. Continental Ins. Co. (2012) 55 Cal.4th 186, 191
(Continental)), pursuant to which each policy triggered during a
long-tail injury is potentially liable for the total amount of the
loss, regardless of whether a portion of the loss occurred outside
the policy’s coverage period. The rule “envisions that each
successive insurer is potentially liable for the entire loss up to
its policy limits. When the entire loss is within the limits of one
policy, the insured can recover from that insurer, which may
then seek contribution from the other insurers on the risk
during the same loss.” (Id. at p. 200.)
Third, in Continental, supra, 55 Cal.4th 186, we construed
language in standard CGL policies to permit “stacking,” which
allows an insured “to add together the maximum limits of all
consecutive policies that [were] in place during the [period of
continuous injury].” (12 Couch on Insurance (3d ed. 2010)
§ 169:5; see Continental, at p. 200 [“ ‘stacking’ generally refers
to the stacking of policy limits across multiple policy periods
that were on a particular risk”].) In other words, “ ‘[w]hen the

3
In Armstrong World Industries, Inc. v. Aetna Casualty &
Surety Co. (1996) 45 Cal.App.4th 1, the court held that asbestos-
related bodily injury claims qualify as a form of continuing
injury that triggers all policies “ ‘in effect from [the claimant’s]
first exposure to asbestos or asbestos-containing products until
date of death or date of claim, whichever occurs first[.]’ ” (Id. at
p. 43.) The parties appear to assume (at least for the purposes
of this appeal) that Armstrong states the proper trigger rule for
asbestos-related injury claims. We will do the same.

8
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

policy limits of a given insurer are exhausted, [the insured] is
entitled to seek indemnification from any of the remaining
insurers [that were] on the risk [during the continuous period of
injury].’ ” (Continental, at p. 200.) If, for example, an insured
purchased 10 annual policies that each had a coverage limit of
$1 million, and all the policies were triggered by a continuous
injury, the insured would be permitted to stack all of the policies
to collect up to $10 million in total coverage. (See id. at p. 201
[the “all-sums-with-stacking indemnity principle . . . ‘effectively
stacks the insurance coverage from different policy periods to
form one giant “uber-policy” with a coverage limit equal to the
sum of all purchased insurance policies’ ”].)
In adopting this all-sums-with-stacking approach,
however, we have cautioned that “future . . . contracting parties
can write into their policies whatever language they agree upon,
including limitations on indemnity, equitable pro rata coverage
allocation rules, and prohibitions on stacking.” (Continental,
supra, 55 Cal.4th at p. 202.)
B. Summary of Kaiser’s Insurance Policies
Having summarized general principles of insurance law
relating to continuous injuries, we turn now to the specific facts
at issue in this appeal. During the relevant time period, Kaiser
purchased primary and excess CGL insurance from numerous
different insurers. “Primary insurance refers to the first layer
of coverage, whereby ‘liability attaches immediately upon the
happening of the occurrence that gives rise to liability.’ ”
(Montrose III, supra, 9 Cal.5th at p. 222.) “Primary insurers
generally have the primary duty of defense.” (Olympic Ins. Co.
v. Employers Surplus Lines Ins. Co. (1981) 126 Cal.App.3d 593,
597.) “Excess insurance, by contrast, ‘refers to indemnity

9
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

coverage that attaches upon the exhaustion of underlying
insurance coverage for a claim.’ [Citation.] An excess insurer’s
coverage obligation begins once a certain level of loss or liability
is reached; that level is generally referred to as the ‘ “attachment
point” ’ of the excess policy.” (Montrose III, at pp. 222–223.)
Kaiser’s primary insurers included Fireman’s Fund
Insurance Company (Fireman’s Fund) (1947–1964), Truck (1964
to 1983), Home Insurance Company (1983–1985) and National
Union Fire Insurance Company (1985–1987). The primary
policy that Truck issued for the 1974–1975 period provided a
“per occurrence” limit of $500,000, meaning that Truck would
provide up to $500,000 of coverage for each claim alleging
injurious exposure to asbestos. However, the policy did not
include any aggregate limit of coverage. In contrast, all the
primary policies issued by non-Truck insurers did contain an
aggregate limit on coverage.
Kaiser also obtained first-level excess policies from
multiple insurers. The first-level excess policies that are the
subject of Truck’s contribution claim were issued for policy years
in which Truck was not the primary insurer. London Market
Insurers (LMI) provided first-level excess policies during the
years that Fireman’s Fund was the primary insurer (1947 to
1964), while First State (1983–1984) and Westchester Fire
(1984–1985) each provided a first-level excess policy during the
years that Home Insurance Company was the primary insurer.
Each of the first-level excess policies include language
stating that coverage will not attach until Kaiser has exhausted
underlying primary policies that are listed in a schedule of
underlying insurance. The policies require Kaiser to maintain
those scheduled primary policies during the relevant period of

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

coverage. Each excess policy also includes an “other insurance”
provision that states, in a variety of ways, that the insured must
also exhaust any “other insurance” or “other underlying
insurance” before the excess policy can be accessed.4
C. Procedural History
Kaiser assigned all asbestos-related bodily injury claims
that triggered Truck’s 1974 primary policy — which presumably
includes any claims alleging that the claimant’s initial exposure
to asbestos occurred in or before 1974 (see ante, p. 8, fn. 3) — to
the 1974 policy. According to the excess insurers, Kaiser
selected Truck’s 1974 policy because it “has no aggregate limit,
does not require Kaiser to pay an allocated share of defense (like
Truck’s other primary policies), and . . . has the lowest
deductible per occurrence ($5,000).” Truck subsequently
entered into agreements with the other primary insurers to
share defense and indemnity costs.
1. Kaiser Cement and Gypsum Corp. v. Insurance
Co. of Pennsylvania (Apr. 8, 2013, B222310)
(nonpub. opn.)
Truck initiated this litigation in 2001 to determine its
coverage obligations to Kaiser. In a prior appeal, Kaiser Cement
and Gypsum Corp. v. Insurance Co. of Pennsylvania (Apr. 8,
2013, B222310) (review den. and opn. ordered nonpub. July 17,
2013) (Kaiser Cement), the Court of Appeal decided two issues

4
The specific wording of these “other insurance” clauses is
explored in more detail below.

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

that have relevance to the current dispute.5 First, the court held
that Kaiser could not access a 1974 first-level excess policy that
sat over Truck’s 1974 primary policy until Kaiser had
horizontally exhausted every primary policy issued during the
claimant’s period of continuous damage. In support, the court
relied on language in the excess policy stating that the insurer’s
indemnity obligations would attach upon exhaustion of Truck’s
1974 primary insurance plus the “ ‘ “applicable limit(s) of any
other underlying insurance collectible by the insured.” ’ ”
(Italics omitted.) Following the reasoning of Community
Redevelopment Agency v. Aetna Casualty & Surety Co. (1996)
50 Cal.App.4th 329 (Community Redevelopment) — a case we
discuss in more detail below — the court explained that the
“policy’s reference to ‘any other underlying insurance’
necessarily means ‘whatever’ . . . primary insurance is available
to Kaiser — not, as Kaiser suggests, only that primary
insurance that expressly covers the 1974 policy year.”
Second, the court ruled that Truck’s 1974 primary policy
included an anti-stacking provision that prohibited Kaiser from
obtaining coverage from any of the other primary policies Truck
had issued between 1964 and 1983. Although the court
acknowledged that insureds are generally permitted to stack
successive policies (see Continental, supra, 55 Cal.4th at p. 200;
ante, at pp. 8–9), it reasoned that Truck’s 1974 policy contained
language that expressly prohibited Kaiser from receiving

5
An unpublished decision may be cited “[w]hen the opinion
is relevant under the doctrines of law of the case, res judicata,
or collateral estoppel.” (Cal. Rules of Court, rule 8.1115(b)(1).)
Kaiser Cement is relevant here as law of the case and we cite it
solely for that reason.

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

indemnification from any other policy that Truck had issued. As
a result of the court’s ruling, Truck’s total indemnity obligation
for each asbestos claim triggering the 1974 policy was only
$500,000, which was substantially less than the $8.3 million per
claim that the excess insurers allege Truck would have been
obligated to pay if Kaiser was allowed to stack all 19 of its Truck
policies. In subsequent litigation, it was determined that all
primary policies issued by non-Truck insurers had been
exhausted as of 2004.
Thus, the Kaiser Cement decision had two important
effects on the insurance coverage litigation. First, the court’s
interpretation of the “other insurance” provision in Kaiser’s
1974 first-level excess policy effectively precluded Kaiser from
accessing any of its excess insurance until it had exhausted
every primary policy issued during the period of continuous
injury. Second, Kaiser could not obtain coverage from any of the
primary policies that Truck had issued other than the 1974
policy. As a result of those rulings, and the subsequent
exhaustion of all primary policies that had been issued by non-
Truck insurers, Truck’s 1974 policy is currently the only
primary insurance that remains available to Kaiser for any
asbestos-related bodily injury claim alleging initial exposure in
or before the 1974–1975 policy period. As noted, that policy
requires Truck to provide up to $500,000 for each asbestos claim,
with any amounts exceeding that level going to excess
insurance. Following Kaiser Cement, various excess insurers
entered into an agreement with Kaiser regarding the funding of
the excess portion of any individual claims that exceed Truck’s
$500,000 obligation.

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

2. Current litigation
At some point after it was determined that Truck’s 1974
policy was the only remaining primary insurance (but before we
had decided Montrose III), Truck filed the current equitable
contribution claim against each of the first-level excess insurers
that sit above the now-exhausted primary policies that were
issued by non-Truck insurers. Presenting arguments that are
substantially similar to those that Kaiser had raised in Kaiser
Cement, Truck argued that the first-level excess insurers’
indemnity obligations to Kaiser attached upon exhaustion of the
directly underlying primary policies. Truck further contended
that because the excess insurers’ coverage obligations had been
triggered, they should be ordered to “contribute to Truck’s
indemnity and defense obligations under the 1974 policy.” The
excess insurers, however, argued there was no basis for
contribution because all of the applicable excess policies
contained “other insurance” provisions that conditioned
coverage on the exhaustion of all available underlying primary
insurance that had been issued during the continuous period of
damage, which necessarily included Truck’s 1974 primary
policy.
Following a bench trial in 2016, the trial court issued an
order denying Truck’s contribution request. Citing Community
Redevelopment, supra, 50 Cal.App.4th 329, and the Kaiser
Cement decision previously issued in this litigation (see ante, at
pp. 11–13), the trial court agreed with the excess insurers that
the “other insurance” provisions in the first-level excess policies
called for horizontal exhaustion of all primary insurance,
including Truck’s 1974 primary policy. The trial court further
reasoned that because the excess insurers’ policies did not

14
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

attach until Truck’s 1974 primary policy was exhausted, there
was no possible basis for Truck to receive contribution.
While Truck’s appeal of the order denying contribution
was pending, we issued our decision in Montrose III, supra,
9 Cal.5th 215. As discussed in more detail below, Montrose III
held that an insured’s excess insurance policies required only
vertical exhaustion, meaning that the insurers’ indemnity
obligations attached as soon as the insured had exhausted any
excess policies with lower attachment points that had been
issued for the same policy year. In reaching that conclusion, we
rejected the excess insurers’ contention that the policies’ “other
insurance” provisions required horizontal exhaustion of all
excess policies with lower attachment points that had been
issued during the period of continuous injury.
On appeal, Truck argued that Montrose III’s
interpretation of “other insurance” policies had effectively
rejected (and overruled) the Court of Appeal’s analysis in
Community Redevelopment and Kaiser Cement. Truck noted
that a recent appellate decision, SantaFe, supra, 52 Cal.App.5th
19, had reached exactly that conclusion in a coverage dispute in
which the insured had sought access to a first-level excess policy
immediately upon exhaustion of the directly underlying primary
policy. The SantaFe court held that Community Redevelopment
and other decisions that had embraced horizontal exhaustion
based on “other insurance” provisions had “rel[ied] on an
interpretation of policy language rejected by the Supreme Court
in Montrose III.” (SantaFe, at p. 30.)
The Court of Appeal, however, disagreed with Truck and
expressly rejected SantaFe’s application of Montrose III. In the
court’s view, Montrose III’s interpretation of “other insurance”

15
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

provisions was limited to situations involving “multiple layers
of excess insurance” and had no application to “layers of primary
and excess insurance.” In support, the court noted the
“qualitative[]” distinctions between primary and excess
insurance. According to the court, whatever effect “other
insurance” clauses might have in other contexts, for purposes of
first-level excess policies that sit over primary insurance, such
provisions were most reasonably construed to include any
primary policies that had been issued during the relevant period
of continuous injury.
Having concluded that the first-level excess insurers did
not owe Kaiser any indemnity obligation until Kaiser had
exhausted every primary policy issued during the period of
continuous damage, the court concluded there was no possible
basis to award Truck contribution. We granted review.
II. DISCUSSION
A. Summary of Applicable Law
We begin our analysis by summarizing legal principles
and prior decisional law that relate to the complex questions of
insurance coverage presented in this appeal.
1. Insurance coverage actions versus contribution
action
We have previously distinguished between two forms of
insurance disputes: insurance coverage actions, which typically
involve a dispute between an insured and an insurer regarding
the insurer’s indemnity and defense obligations, and equitable
contribution claims, in which one insurer seeks recovery from
another insurer that allegedly covered the same risk and failed
to pay its proportionate share. (See, e.g., Dart, supra, 28 Cal.4th

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

at p. 1080 [“the obligation of successive . . . insurers to cover a
continuously manifesting injury is a separate issue from the
obligations of the insurers to each other. . . . ‘[A]pportionment
among multiple insurers must be distinguished from
apportionment between an insurer and its insured’ ”].)
Insurance coverage claims between an insured and its
insurer are a form of contract dispute and thus focus on “the
language of the insurance policies at issue.” (Montrose III,
supra, 9 Cal.5th at pp. 229–230.) “ ‘ “Our goal in construing
insurance contracts, as with contracts generally, is to give effect
to the parties’ mutual intentions. [Citations.] ‘If contractual
language is clear and explicit, it governs.’ [Citations.] If the
terms are ambiguous [i.e., susceptible of more than one
reasonable interpretation], we interpret them to protect ‘ “the
objectively reasonable expectations of the insured.” ’ ” ’
[Citation.] If these rules do not resolve an ambiguity, we may
then ‘ “resort to the rule that ambiguities are to be resolved
against the insurer.” ’ ” (Id. at p. 230, bracketed text in
original.) “ ‘Because the insurer writes the policy, it is held
“responsible” for ambiguous policy language, which is therefore
construed in favor of coverage.’ ” (Montrose I, supra, 10 Cal.4th
at p. 667.)
“[A]n equitable contribution claim between coinsurers[, in
contrast,] is not based upon contract, but instead involves
‘ “equitable principles designed to accomplish ultimate justice in
the bearing of a specific burden” ’ ” (Axis, supra,
204 Cal.App.4th at pp. 1227–1228, quoting Signal, supra,
27 Cal.3d at p. 369.) “In the insurance context, the right to
contribution arises when several insurers are obligated to
indemnify or defend the same loss or claim, and one insurer has

17
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

paid more than its share of the loss or defended the action
without any participation by the others. . . . The purpose of this
rule of equity is to accomplish substantial justice by equalizing
the common burden shared by coinsurers, and to prevent one
insurer from profiting at the expense of others.” (Fireman’s
Fund Ins. Co. v. Maryland Casualty Co. (1998) 65 Cal.App.4th
1279, 1293 (Fireman’s Fund).)
Under California law, there is no “definitive rule” that
governs equitable contribution. (Signal, supra, 27 Cal.3d at
p. 369.) Rather, when evaluating a contribution claim, courts
should consider a variety of factors, including “the particular
policies of insurance, the nature of the claim made, . . . the
relation of the insured to the insurers” (ibid.) and “ ‘any other
equitable considerations.’ ” (Unigard, supra, 79 Cal.App.4th at
p. 974.) Although equitable contribution claims are not
“ ‘controlled by the language of [the insurers’] contracts with the
respective policy holders’ ” (Signal, at p. 369), we have
emphasized that the policy language nonetheless remains an
important factor. (See ibid. [courts should not impose
contribution on an insurer that “contraven[es] . . . the provisions
of its policy” absent “some compelling equitable consideration”];
Unigard, at p. 978.) As explained by one court, “if [an] insurer
never had an obligation to provide coverage, it would be
extremely unfair to enforce a contribution action.” (Axis, supra,
204 Cal.App.4th at p. 1228.)
2. Contribution between primary and excess insurers
In the context of traditional “noncontinuous injury”
insurance claims — meaning a claim that implicates only a
single policy period — it has long been the rule that there is “no
contribution between a primary and excess carrier without a

18
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

specific agreement to the contrary.” (Reliance Nat. Indemnity
Co. v. General Star Indemnity Co. (1999) 72 Cal.App.4th 1063,
1080; see Fireman’s Fund, supra, 65 Cal.App.4th at p. 1294,
fn. 4.) The basis for that rule is rooted in the purpose of
contribution, which is to “equaliz[e] the common burden”
(Fireman’s Fund, at p. 1293) shared by coinsurers that “share
the same level of liability on the same risk as to the same
insured.” (Maryland Casualty Co. v. Nationwide Mutual Ins.
Co. (2000) 81 Cal.App.4th 1082, 1089 (Maryland); see Morgan
Creek Residential v. Kemp (2007) 153 Cal.App.4th 675, 684
[contribution applies only when there is a “ ‘common burden of
liability’ ”].) When a claim implicates only a single policy period,
and an excess policy provides that the insurer’s coverage
obligations attach upon exhaustion of the primary insurance
listed in the schedule of underlying insurance, the excess and
primary insurer cannot be said to “share the same level of
liability.” (Maryland, at p. 1089.)
That analysis becomes more complicated in the context of
continuous injuries, which extend over multiple policy periods.
In that circumstance, the question arises whether the excess
insurers’ indemnity obligations to the insured attach: (1) only
after the exhaustion of all primary layers of insurance issued
during the continuous period of injury (horizontal exhaustion);
or (2) whether attachment occurs upon exhaustion of the
directly underlying primary insurance that was issued during
the same policy year (vertical exhaustion). If the excess insurers
have no coverage obligation until all primary policies have
exhausted (horizontal exhaustion), it follows that the excess
insurer cannot be said to be on the same level of liability as any
of the primary insurers, thus precluding any basis for

19
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

contribution between the two types of insurers. In effect,
horizontal exhaustion results in the same situation between
excess and primary insurers that occurs where a claim
implicates only one policy period: the excess insurer and
primary insurer remain on distinct levels of liability, with the
excess insurer’s obligations being triggered only after the
primary coverage is exhausted, thus precluding contribution.
Under vertical exhaustion, however, the excess insurer
owes an indemnity obligation to the insured as soon as the
directly underlying primary policy has exhausted. That is true
even if primary insurance issued for a precedent or subsequent
policy period remains unexhausted (and thus available to the
insured). Thus, unlike the situation with horizontal exhaustion,
under a rule of vertical exhaustion, a first-level excess insurer
from one policy period and a primary insurer from a different
policy period might simultaneously owe coverage to the same
insured for the same injury. In that situation, it becomes less
clear that the excess insurer remains on a different “level of
liability” (Maryland, supra, 81 Cal.App.4th at p. 1089) than
primary insurers that issued unexhausted policies during
different periods of the continuous injury.
Prior to our decision in Montrose III, supra, 9 Cal.5th 215,
the leading case addressing contribution between primary and
excess injuries in the continuous injury context was Community
Redevelopment, supra, 50 Cal.App.4th 329. The insured in
Community Redevelopment obtained annual primary policies
from United between 1982–1985. For the 1985–1986 period, the
insured obtained a primary policy from State Farm and a first-
level excess policy from Scottsdale. The Scottsdale policy stated
that its indemnity obligations would attach upon exhaustion of

20
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

the underlying State Farm policy “ ‘plus the applicable limits of
any other underlying insurance collectible by the insured.’ ” (Id.
at p. 335, italics and capitalization omitted.)
State Farm entered a settlement on behalf of the insured
that exhausted the limits of its 1985–1986 primary policy.
United thereafter brought a contribution action against
Scottsdale, contending “that Scottsdale had a duty to . . .
contribute to the primary coverage burden as soon as State
Farm’s underlying primary policy was exhausted. According to
United, Scottsdale’s policy was expressly excess to State Farm’s
policy; as soon as the latter was exhausted, Scottsdale’s duty
arose and the existence of other primary coverage was
irrelevant.” (Community Redevelopment, supra, 50 Cal.App.4th
at p. 337.)
The court rejected that argument, explaining that “[i]t is
settled under California law that an excess or secondary policy
does not cover a loss, nor does any duty to defend the insured
arise, until all of the primary insurance has been exhausted.”
(Community Redevelopment, supra, 50 Cal.App.4th at p. 339.)
In support, the court cited case law that addressed excess
coverage in the context of noncontinuous injury claims (i.e.,
injuries that triggered only one policy period). The courts in
those cases ruled that first-level excess policies containing
“other insurance” provisions required not only the exhaustion of
the primary insurance expressly listed in the excess policy, but
also any other primary insurance the insured had obtained for
that period. (See ibid.)
The Community Redevelopment court concluded that
“other insurance” provisions should apply the same way in the
context of a continuous injury that triggers multiple policy

21
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

periods. According to the court, the “other insurance” provision
in Scottsdale’s excess policy made clear that the coverage was
purchased “as excess to the . . . primary policy issued by State
Farm” and “ ‘any other underlying insurance collectible by the
[insured parties].’ ” (Community Redevelopment, supra,
50 Cal.App.4th at p. 338, italics omitted.) In the court’s view,
“[t]he only reasonable interpretation of this policy language is
that the term ‘underlying insurance’ must be read to include all
available primary insurance, not just the policy expressly listed
on the schedule of underlying insurance.” (Id. at p. 341.) The
court reasoned that because Scottsdale’s excess policy called for
horizontal exhaustion of all primary insurance, Scottsdale
remained on a different level of liability than United’s primary
policy, thus precluding contribution.
As noted above, the Court of Appeal in this case (and in its
prior Kaiser Cement decision) chose to follow the reasoning of
Community Redevelopment, concluding both that: (1) the “other
insurance” provisions unambiguously compelled a rule of
horizontal exhaustion; and (2) because the first-level excess
insurers owed no coverage obligation to the insured until all
primary insurance had exhausted, there was no possible basis
for Truck to obtain contribution.6

6
Although the Court of Appeal’s decision denying
contribution in the instant matter did not rely on its prior ruling
regarding horizontal exhaustion set forth in the Kaiser Cement
appeal, the excess insurers nonetheless contend that Kaiser
Cement’s ruling on horizontal exhaustion is now “law of the
case” and cannot be relitigated here. The law of the case
doctrine generally “precludes a party from obtaining appellate

22
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

3. Montrose III
In Montrose III, supra, 9 Cal.5th 215, we addressed the
application of “other insurance” provisions in the context of
excess policies issued during successive periods of a continuous
injury. The insured was sued for causing continuous
environmental contamination between 1947 and 1982. During
that period, the insured obtained annual policies for primary
insurance and multiple layers of excess insurance. The parties
stipulated that all primary insurance had been exhausted. The
question we had to decide was “the sequence in which [the
insured could] access the excess insurance policies covering this
period.” (Id. at p. 222.) The insured sought a rule of vertical
exhaustion, which would allow it to access an excess insurance
policy upon the exhaustion of any excess policies with lower
attachment points that had been issued for the same policy

review of the same issue more than once in a single action.”
(Katz v. Los Gatos-Saratoga Joint Union High School Dist.
(2004) 117 Cal.App.4th 47, 62.) It is well-settled, however, that
the doctrine may be disregarded where the “controlling rules of
law have been altered or clarified by a decision intervening
between the first and second appellate determinations.” (People
v. Stanley (1995) 10 Cal.4th 764, 787.) Even assuming that
application of law of the case would otherwise be appropriate,
we are satisfied — as apparently was the Court of Appeal —
that our intervening decision in Montrose III, supra, 9 Cal.5th
215, justifies departure from the doctrine here.
We also find no merit in the excess insurers’ contention
that various arguments and admissions Truck made in the
Kaiser Cement appeal regarding the anti-stacking issue
judicially estop Truck from now arguing that under Montrose
III, supra, 9 Cal.5th 215, the first-level excess policies should be
construed as attaching upon exhaustion of the directly
underlying primary policy.

23
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

period. The insurer sought a rule of horizontal exhaustion,
which would not allow the insured to access an excess policy
until it had exhausted every excess policy with a lower
attachment point that had been issued during the continuous
period of injury. (See id. at p. 229.)
The dispute centered on the meaning of “other insurance”
clauses in the excess insurance policies. Those clauses provided,
in varying ways, that the policies shall be excess to “other
insurance” or “ ‘other underlying insurance’ ” (Montrose III,
supra, 9 Cal.5th at pp. 224–225, italics omitted) available to the
insured, “whether or not the other insurance is specifically listed
in the policy’s schedule of underlying insurance.” (Id. at p. 230.)
Citing Community Redevelopment, supra, 50 Cal.App.4th 329,
the insurers argued that the “other insurance” clauses “call[ed]
for a rule of horizonal exhaustion because they restrict
indemnification from any excess policy until the insured has
exhausted all other available insurance — which, in a case of
long-tail injury, means every policy with a lower attachment
point from every policy period triggered by the continuous
injury.” (Montrose III, at p. 230.) The insureds, however,
argued that the “other insurance” clauses were intended to refer
only to “other insurance” policies with lower attachment points
that were in effect during the same policy period as the
overlaying excess policy. (See id. at pp. 230–231.)
While finding that both parties had offered reasonable
interpretations of the “other insurance” provisions (see Montrose
III, supra, 9 Cal.5th at pp. 230, 234), we ultimately concluded
that when read “in light of background principles of insurance
law, and considering the reasonable expectations of the parties”
(id. at p. 222), the policy language was “most naturally read to

24
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

mean that [the insured] may access its excess insurance
whenever it has exhausted the other directly underlying excess
insurance policies that were purchased for the same policy
period” (id. at p. 234).
Turning first to the text of the “other insurance”
provisions, we found that certain characteristics weighed
against the excess insurers’ assertion that such language
unambiguously mandated a rule of horizontal exhaustion.
First, none of the policies contained any language “clearly or
explicitly stat[ing] that [the insured] must exhaust insurance
with lower attachment points purchased for different policy
periods.” (Montrose III, supra, 9 Cal.5th at p. 230.) Second, we
noted that some formulations of the “other insurance” clauses
included broad language that, “[i]f . . . read to apply to
insurance purchased for other policy periods, . . . could fairly be
understood to require the exhaustion of every other insurance
policy at every attachment point — not merely, as the insurers’
theory of horizontal exhaustion would have it, excess policies
from other policy periods that contain lower attachment points.”
(Id. at p. 231.) Third, we explained that contrary to the excess
insurers’ proposed interpretation, our prior decisions (and the
decisions of several other jurisdictions) made clear that “other
insurance” provisions “have not traditionally been used to
address questions concerning the obligation of successive
insurers to indemnify policyholders for a continuously
manifesting injury.” (Id. at p. 232.) Instead, such clauses have
historically been understood to “address ‘[a]llocation questions
with respect to overlapping concurrent policies.’ ” (Ibid.)
Looking next to the text of the excess policies as a whole,
we found that “other aspects of the insurance policies strongly

25
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

suggest[ed] that the exhaustion requirements were meant to
apply to directly underlying insurance and not to insurance
purchased for other policy periods.” (Montrose III, supra,
9 Cal.5th at p. 233.) First, we noted that many of the policies
“explicitly state their attachment point, generally by referencing
a specific dollar amount of underlying insurance in the same
policy period that must be exhausted.” (Ibid.) We explained
that under the “insurers’ theory of horizontal exhaustion,” there
would be no coverage until the insured had exhausted that
attachment amount “for every relevant policy period” (ibid.),
thus substantially increasing the “operative attachment point”
well beyond what the terms of the policy suggested.
Second, and “[r]elatedly” (Montrose III, supra, 9 Cal.5th at
p. 234), we noted that the excess policies “regularly include or
reference schedules of underlying insurance — all for the same
policy period” (ibid.). We explained that under the insured’s
reading, “these schedules provide a presumptively complete list
of insurance coverage that must be exhausted before the excess
policy may be accessed, with the ‘other insurance’ clauses
serving as a backstop to prevent double recovery in the rare
circumstance where underlying coverage changes after the
excess policy is written. [Citation.] But under the insurers’ rule
of horizontal exhaustion, these schedules would represent only
a fraction — perhaps only a small fraction — of the insurance
policies that must be exhausted before a given excess policy may
be accessed.” (Ibid.)
Looking beyond the language of the parties’ policies, we
further concluded that “[c]onsideration of the parties’
reasonable expectations favors a rule of vertical exhaustion
rather than horizontal exhaustion.” (Montrose III, supra,

26
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

9 Cal.5th at p. 234.) First, we noted that “applying the
horizontal exhaustion rule would be far from straightforward”
given the lack of “standardization” between the excess policies
on issues such as attachment points, level of coverage and
specific terms and conditions. (Ibid.) To illustrate the
complexity, we noted that “the first layer of excess insurance in
1984 . . . would appear to reach as high as the 13th layer of
excess coverage in 1974. To which horizontal layer does the
1984 policy belong? The policies do not say. Nor does anything
in the text of these policies tell us how an ‘other insurance’
clause in a policy from one period ought to apply to a policy from
another period that contains both a lower attachment point and
a higher coverage limit. The policies’ silence on these basic,
foundational questions tends to undermine the idea the parties
expected such a rule to apply.” (Id. at p. 235.)
We also noted that because “exclusions, terms, and
conditions may vary from one policy to another, a rule of
horizontal exhaustion would create significant practical
obstacles to securing indemnification. . . . Such a rule would put
the insured to the considerable expense of establishing a right
to coverage under the definitions, terms, conditions, and
exclusions from policies in every policy period triggered by the
continuous injury. Coverage under less restrictive policies
would be delayed until more restrictive policy terms are
adjudicated. In sum, ‘[h]orizontal exhaustion would create as
many layers of additional litigation as there are layers of
policies.’ ” (Montrose III, supra, 9 Cal.5th at p. 235.)
We rejected the excess insurers’ contention that a rule of
vertical exhaustion would frustrate the parties’ reasonable
expectations by unfairly requiring “a single insurer to shoulder

27
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

the burden” of indemnifying “ ‘decades’ worth of environmental
damage.’ ” (Montrose III, supra, 9 Cal.5th at p. 236.) We noted
that this argument was “not different in kind from arguments
we have already considered and rejected in adopting the all-
sums-with-stacking approach to the coverage of long-tail
injuries” (ibid.), explaining that “[t]here is no evident unfairness
to insurers when their insureds incur liabilities triggering
indemnity coverage under the negotiated policy contract” (ibid.).
We further explained that a rule of vertical exhaustion “does not
alter the usual rules of equitable contribution between insurers.
An insurer required to provide excess coverage for a long-tail
injury may lessen its burden by seeking reimbursement from
other insurers that issued policies during the relevant period.”
(Ibid.)
We also rejected the insurers’ reliance on Community
Redevelopment, supra, 50 Cal.App.4th 329, explaining that a
contribution action between a primary insurer and an excess
insurer presented “a meaningfully different scenario” than a
coverage action between an insured and its excess insurers, and
thus “offer[ed] no real lessons for resolving the question now
before us.” (Montrose III, supra, 9 Cal.5th at p. 237.) In a
footnote, we emphasized that because the question had not been
presented, we need not “decide when or whether an insured may
access excess policies before all primary insurance covering all
relevant policy periods has been exhausted.” (Id. at p. 226,
fn. 4.)
B. Analysis
As in Montrose III, we are faced with questions regarding
whether language in standard CGL excess insurance policies
impose a rule of vertical or horizontal exhaustion in the context

28
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

of continuous injury insurance claims. The Court of Appeal
concluded that because the excess policies at issue in this case
sat above primary insurance, they were most reasonably
construed as requiring the insured (Kaiser) to horizontally
exhaust all primary insurance, including Truck’s 1974 policy.
The court further reasoned that because the excess policies did
not create any coverage obligation until Truck’s policy was
exhausted, there was no possible basis for Truck to receive
contribution.
Given that the court’s contribution analysis turns entirely
on its interpretation of the first-level excess policies, we will
begin our review by assessing the court’s construction of those
contracts, which is “a question of law” to which we apply
independent review. (E.M.M.I. Inc. v. Zurich American Ins. Co.
(2004) 32 Cal.4th 465, 470.)7

7
The excess insurers argue that because this case involves
a claim for equitable contribution, we should apply an abuse of
discretion standard of review. While it is true that our courts
have applied a deferential standard to some aspects of equitable
contribution awards that are not at issue in this case (such as
the trial court’s chosen method for allocating a loss among
insurers), the Court of Appeal’s interpretation of the excess
policies remains a question of law to which we apply de novo
review. (Compare Fireman’s Fund, supra, 65 Cal.App.4th at
p. 1308 [“trial court’s determination of the correct allocation
[method] . . . for purposes of contribution” is reviewed for abuse
of discretion] with Truck Ins. Exchange v. AMCO Ins. Co. (2020)
56 Cal.App.5th 619, 629 [applying de novo review where
contribution claim turned on interpretation of insurance
policies]; Certain Underwriters at Lloyds, London v. Arch
Specialty Ins. Co. (2016) 246 Cal.App.4th 418, 429 [“Although
equitable contribution may call for judicial discretion, here the

29
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

1. The Court of Appeal erred in interpreting the
policy language
As was the case in Montrose III, the Court of Appeal’s
interpretation of the excess policies centered on the meaning of
the “other insurance” clauses in the excess insurance policies.
The text of those clauses are as follows:
• The LMI policies in effect from 1953–1958 provide that
liability shall attach only after the primary insurers
listed in the schedule of underlying insurance have paid
“the full amount of their respective ultimate loss,” and
then define “ultimate net loss” as “the sums paid in
settlement of losses for which the Assured is liable after
making deductions for all recoveries, salvages and
other insurances (other than recoveries under the
policy/ies of the [scheduled primary insurers]), whether
recoverable or not” (italics added);
• The LMI policies in effect from 1958–1964 include an
independent “Other Insurance” clause that provides:
“If other valid and collectible insurance with any other
insurer is available to the Assured covering a loss also
covered by this policy, other than insurance that is in
excess of the insurance afforded by this policy, the
insurance afforded by this policy shall be in excess of
and shall not contribute with other insurance”;
• The First State policy in effect from 1983–1984
provides that the Company shall be liable for loss in
excess of “an amount equal to the limits of liability

trial court expressly stated it decided the matter as a question
of law, and our review is de novo”].)

30
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

indicated beside the underlying insurance listed in the
Schedule A of underlying insurance, plus the applicable
limits of any other underlying insurance collectible by
the insured”; “[i]f other collectible insurance with any
other insurer is available to the insured covering in loss
covered here [sic], except insurance purchased to apply
in excess of the sum of [this policy], the insurance
hereunder shall be in excess of and not contribute with
such other insurance” (italics added).8
Following the analysis in Community Redevelopment,
50 Cal.App.4th 329, the court interpreted these “other
insurance” provisions as unambiguously requiring Kaiser to
exhaust all primary policies that it had purchased for every
policy period triggered by the continuous injury. Truck,
however, contends that our core holding in Montrose III — that
standard “other insurance” provisions appearing in excess
policies are only intended to refer to insurance purchased for the
same policy period — applies equally in the context of excess
policies that sit over primary insurance. As discussed in more
detail below, we agree with Truck that the policy language at
issue here cannot be meaningfully distinguished from the
policies that we addressed in Montrose III. We also agree that
the qualitative distinctions between primary and excess
insurance do not justify assigning an entirely different meaning
to standardized “other insurance” clauses merely because the
excess policy sits over primary insurance rather than another
level of excess insurance.

8
The Westchester policy in effect from 1984–1985 includes
language that is essentially identical to the First State policy.

31
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

The Court of Appeal made no attempt to differentiate the
text of the “other insurance” provisions at issue here and those
at issue in Montrose III. Nor have the excess insurers attempted
to do so in their briefing. That is not particularly surprising
given that the provisions are substantially identical, and in
several formulations exactly identical,9 each providing in
various ways that the excess policy shall be excess to the
underlying primary policy identified in the schedule of
underlying insurance along with any “other insurance” or “other
underlying insurance” available to the insured. As in Montrose
III, none of the provisions explicitly reference “other insurance”
purchased for different policy periods.
Our observations in Montrose III regarding the historical
use of “other insurance” provisions also weigh against the excess

9
For example, one of formulations at issue in Montrose III
provided that “ ‘[i]f other valid and collectible insurance with
any other insurer is available to the Insured covering a loss also
covered by this policy, other than insurance that is in excess of
the insurance afforded by this policy, the insurance afforded by
this policy shall be in excess of and shall not contribute with
such other insurance.’ ” (Montrose III, supra, 9 Cal.5th at
pp. 224–225.) Several of the LMI policies at issue in this case
include an identically worded provision. (See ante, at p. 30.) A
second formulation in Montrose III defined the excess insurer’s
attachment point as the total of the liability limits set forth in
the excess policy listed in the schedule of underlying insurance
plus “ ‘the applicable limits of any other underlying insurance
collectible by the insured.’ ” (Montrose III, at p. 224.) The First
State policy at issue in this case likewise defines the attachment
point as the total of the liability limit set forth in the primary
policy listed in the schedule of underlying insurance plus “the
applicable limits of any other underlying insurance collectible by
the insured.” (See ante, at pp. 30–31.)

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TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

insurers’ contention that such language is most reasonably
interpreted as requiring the insured to exhaust primary
insurance that was issued during precedent or successive policy
periods of a continuous injury. As we explained there, such
provisions have historically been understood as referring only to
“other insurance” that was issued for the same policy period, not
(as the excess insurers suggest) other insurance issued “for
different policy periods.” (Montrose III, supra, 9 Cal.5th at
p. 230; see id. at p. 234.) Indeed, as Montrose III noted and we
reiterate here, most jurisdictions that have addressed analogous
arguments have concluded that “ ‘other insurance’ clauses” do
not mandate horizontal exhaustion nor are they otherwise
relevant to policies issued during different periods of coverage.
(Id. at pp. 232–233.) The Restatement of Liability Insurance
likewise explains that “ ‘ “other insurance” ’ clauses have
generally been used to address ‘[a]llocation questions with
respect to overlapping concurrent policies.’ ” (Montrose III, at
p. 232, quoting Rest., Liability Insurance, § 40, com. c, p. 345.)
The excess insurers have presented no argument as to why the
historical understanding of “other insurance” clauses, which is
generally supportive of vertical rather than horizontal
exhaustion, is inapplicable when the excess policy sits over a
primary policy.
The first-level excess policies also share the same general
characteristics that we found in Montrose III to be “strongly
suggest[ive]” of requiring only vertical, not horizontal
exhaustion. (Montrose III, supra, 9 Cal.5th at p. 233.) For
example, the excess policies “include or reference schedules of
underlying insurance — all for the same policy period.” (Id. at
p. 234.) Indeed, every single policy at issue in this case describes

33
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

its attachment point by directly referencing primary insurance
that was issued for the same policy period. As in Montrose III,
we believe these schedules are most reasonably construed as a
“presumptively complete list of insurance coverage that must be
exhausted before the excess policy may be accessed, with the
‘other insurance’ clauses serving as a backstop to prevent double
recovery in the rare circumstance where underlying coverage
changes after the excess policy is written.” (Ibid.)10
Moreover, several of the policies not only refer to
underlying primary insurance issued during the same policy
period, but also “referenc[e] a specific dollar amount of
underlying insurance in the same policy period that must be
exhausted.” (Montrose III, supra, 9 Cal.5th at p. 233.) Under
the excess insurers’ theory of horizontal exhaustion, however,
this attachment would not occur until Kaiser had exhausted
that amount, plus the limits of every other primary policy it had
obtained for every relevant policy period.
Furthermore, the same practical concerns with
administering a rule of horizontal exhaustion that we discussed
in Montrose III are likewise implicated here. We explained, for
example, that applying horizontal exhaustion would be “far from
straightforward” given that the attachment points of the
insured’s layers of excess insurance did not align from policy
year to policy year. (Montrose III, supra, 9 Cal.5th at p. 234.)

10
The first-level excess policies also include provisions
stating that upon exhaustion of those scheduled underlying
policies, the excess policy shall “continue in force as underlying
insurance.” Again, these express references to the directly
underlying primary policies tend to support a view of vertical,
rather than horizontal exhaustion.

34
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

The Court of Appeal concluded this rationale was inapplicable
in the current context because “there is only one underlying
layer of insurance, namely, primary insurance and it is easy to
ascertain whether that insurance has been exhausted.” That
reasoning, however, overlooks that the plain text of the first-
level excess policies’ “other insurance” provisions is not limited
to other underlying primary insurance. Rather, the provisions
speak generally to “any other insurance” or “any other
underlying insurance.” (Italics added.) If the excess insurers
are correct that these provisions were intended to apply to
insurance purchased for different policy periods, their plain
language indicates that Kaiser would have to exhaust any other
underlying insurance — i.e., any policy with a lower attachment
point — not merely any other underlying primary insurance.
While that might not create any particular administrative
complications if the attachment points of Kaiser’s first-level
excess policies were standardized across policy years, the record
shows that is not the case. Rather, as in Montrose III, the first-
level excess policies appear to come in different “shapes and
sizes.” (Montrose III, supra, 9 Cal.5th at p. 234.) For example,
in the 1983 policy year, Kaiser obtained primary insurance for
the first $2 million of liability and obtained a first-level excess
policy that attaches above that amount. In 1958, however,
Kaiser obtained only $1 million in primary insurance with a
first-level excess policy for the next $2 million. If the “other
insurance” provisions truly apply across all policy periods, does
Kaiser’s 1983 first-level excess policy (with an attachment point
of $2 million) require Kaiser to exhaust the 1958 primary policy
(with an attachment point of $1 million) and the first $1 million
of the 1958 first-level excess policy? Or can Kaiser access the

35
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

1983 first-level excess policy as soon as the $1 million 1958
primary policy is exhausted? Stated more simply, if the $1
million 1958 primary policy qualifies as “other underlying
insurance” to the 1983 first-level excess policy, why wouldn’t the
initial $1 million of the 1958 first-level excess policy likewise
qualify as underlying insurance that would have to be
exhausted prior to accessing the 1983 policy? As noted in
Montrose III, “[t]he policies’ silence on these basic, foundational
questions tends to undermine the idea the parties expected . . .
a rule [of horizontal exhaustion] to apply.” (Id. at p. 235.)
Finally, Montrose III expressed concern that “because the
exclusions, terms, and conditions may vary from one [excess]
policy to another” (Montrose III, supra, 9 Cal.5th at p. 235), a
rule of horizontal exhaustion would “put the insured to the
considerable expense of establishing a right to coverage under
the definitions, terms, conditions, and exclusions from policies
in every policy period triggered by the continuous injury” (ibid.).
Again, neither the Court of Appeal nor the excess insurers have
provided any explanation as to why those concerns are
inapplicable in the context of primary insurance. During the
relevant time frame Kaiser bought dozens of primary policies
from multiple insurers. While the parties have not provided
detailed information regarding the specific terms of those
policies, the excess insurers’ own briefing indicates that the
terms of the primary policies vary with respect to coverage
amounts, aggregate limits, allocation of defense costs and
deductible requirements. Moreover, as discussed above, Kaiser,
Truck and the excess insurers previously spent years litigating
whether a specific provision in Truck’s 1974 policy barred Kaiser
from accessing any of Truck’s other 18 primary policies (a

36
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

provision apparently absent in the non-Truck primary policies).
Thus, based on the limited record before us, it is reasonable to
assume that the same concerns regarding the amount of
litigation a rule of horizontal exhaustion would create due to
variations in policy terms and conditions are equally present in
the context of primary insurance.11
Despite the textual overlap between the policy language
at issue here and in Montrose III, and the similar practical
complications that a rule of horizontal exhaustion would present
to the insured in the context of primary insurance, the Court of
Appeal concluded that “other insurance” provisions should
nonetheless be assigned a different meaning when the excess
policy sits over primary insurance. The sole reason the court
provided in support of this conclusion was the “qualitative[]”
distinctions between primary and excess insurance. As
explained by the court, primary policies receive higher
premiums because they “attach as first-dollar coverage and have
an immediate obligation to respond,” whereas excess policies
may never be called upon to indemnify. Moreover, primary
insurers generally have the right to control defense and
settlement without input from excess insurers and “do not use

11
Although Kaiser has joined the excess insurers in arguing
that Truck’s contribution claim should be denied on unfairness
grounds, it has notably declined to take a position as to whether
the Court of Appeal properly interpreted the first-level excess
policies as requiring horizontal exhaustion. In the prior Kaiser
Cement appeal, however, Kaiser specifically argued against
such a rule, contending that it was “objectively reasonable” to
expect that its 1974 first-level excess policy would become
available immediately upon exhaustion of the underlying 1974
Truck primary policy.

37
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

defense costs to reduce limits.” The court provided no further
discussion or explanation as to why it believed these distinctions
warranted a departure from the interpretation of “other
insurance” provisions that we adopted in Montrose III. We find
the Court of Appeal’s reasoning unavailing.
In SantaFe, supra, 52 Cal.App.5th 19, the First District
reached a contrary conclusion, reasoning that the distinctions
between primary insurance and excess insurance “provide little
justification for construing the policy language interpreted in
Montrose III differently.” (Id. at p. 28.) Regarding the
differences in the premiums paid for primary and excess
insurance, the court explained that “the evaluation of risk based
on the assumption of vertical exhaustion is straightforward and
can be made based on known parameters. However, if the risk
assessment were to be made based on the assumption of
horizontal exhaustion, the evaluation would be speculative and
unpredictable” as the “level of liability at which the excess
coverage would attach would be unascertainable. . . . The
difference between premiums paid for excess and for primary
policies does not justify an interpretation that renders the point
of attachment so unpredictable and unascertainable when the
policy is issued.” (Id. at p. 29.)
Regarding “the differing defense obligations” between
primary and excess insurance (SantaFe, supra, 52 Cal.App.5th
at p. 29), the court explained that requiring the insured to
exhaust only the directly underlying primary policy does not
alter the “well settled [rule] that an excess insurer [generally]
has no duty to defend unless the underlying primary insurance
is exhausted” (ibid.). The court noted that “[f]rom the
perspective of the insured, one would reasonably expect the

38
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

excess insurer to contribute to the defense once the scheduled
primary policies have been exhausted and the attachment
points reached.” (Ibid.)12
We believe that SantaFe has the better view. We are not
persuaded that the differences in characteristics between
primary and excess insurance is sufficient to demonstrate that
“other insurance” provisions are meant to require horizontal
exhaustion when used in first-level excess policies. As noted,
Montrose III concluded that identical language appearing in
higher-level excess policies is most reasonably construed as
applying only to underlying insurance that covers the same
policy period. We do not believe that the meaning of the
language is transformed to say exactly what we concluded it did
not say in Montrose III merely because the policy sits over
primary insurance rather than another level of excess
insurance.
Furthermore, as SantaFe explained, even under the rule
of vertical exhaustion that we adopted in Montrose III, the
differences in premiums between primary and excess insurance
continue to reflect the fact that the excess insurer still has no
indemnity obligations unless and until the insured exhausts the
limits of the directly underlying primary policy. Given that
these excess policies were written long before we adopted the
all-sums-with-stacking approach to continuous injuries (see
ante, at pp. 7–9), we are dubious that the excess insurers priced

12
The specific defense obligations that a first-level excess
insurer owes to the insured, and whether defense costs are
included in the aggregate limits of the excess policy, will of
course turn on the specific terms of each excess policy.

39
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

their premiums on the assumption that their policies would not
attach until the insured had exhausted the directly underlying
primary policies along with any other primary insurance the
insured might acquire in later years. Were that truly the
insurers’ intent, we would expect a clearer statement than a
mere reference to “other insurance.” (See Montrose I, supra,
10 Cal.4th at p. 647 [“ ‘Because the insurer writes the policy, it
is held “responsible” for ambiguous policy language, which is
therefore construed in favor of coverage’ ”].) While the excess
insurers may not have anticipated the coverage and allocation
rules that have emerged from the Montrose, Aerojet, and
Continental line of decisions, we cannot now rewrite what they
promised to the insured.
We are also dubious that even after our adoption of the all-
sums-with-stacking approach, excess insurers would choose to
price premiums — or that the insured would agree to pay
premiums — based on a horizontal exhaustion approach that
carries the inherent uncertainty of what other primary
insurance the insured might acquire in later years. By raising
the excess policy’s attachment point with each subsequent
primary policy that the insured acquires during the period of
continuous injury, a rule of horizontal exhaustion effectively
operates to penalize the insured for obtaining more insurance.
It is not clear why the insured would agree to such an approach.
Thus, absent clear policy language to that effect, we decline to
read “other insurance” language to reflect such an agreement
between the insured and excess insurer.
In sum, we believe that the language of the first-level
excess policies, when considered in conjunction with the
insured’s reasonable expectations and the historical role of

40
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

“other insurance” provisions, is most naturally read to mean
that the insured may access the policies upon exhaustion of the
directly underlying policies that were purchased for the same
period. Excess insurers do, however, remain free to write their
future excess policies in a manner that expressly requires
horizontal exhaustion. (See Montrose III, supra, 9 Cal.5th at
p. 237 [“Parties to insurance contracts are, of course, free to
write their policies differently to establish alternative
exhaustion requirements or coverage allocation rules if they so
wish”].)
As noted above, Community Redevelopment, supra,
50 Cal.App.4th 329, which predates our decision in Montrose III,
reached a different conclusion. The court there found that
similarly worded “other insurance” provisions required the
insured to horizontally exhaust all primary insurance. As noted
above, in reaching that conclusion, the court relied primarily on
case law that addressed noncontinuous injury claims (i.e.,
claims that triggered only one policy period). (See ante, at
pp. 20–22; Community Redevelopment, at p. 339, citing Olympic
Ins. Co. v. Employers Surplus Lines Ins. Co. (1981)
126 Cal.App.3d 593 [concerning an aircraft collision],
McConnell v. Underwriters at Lloyds (1961) 56 Cal.2d 637
[concerning an automobile collision], and Lamb v. Belt Cas. Co.
(1935) 3 Cal.App.2d 624 [concerning an automobile collision].)
The courts in those cases held that the excess policies’ “other
insurance” provisions required the insured to exhaust not only
the underlying primary insurance expressly listed in the excess
policy, but also any other underlying primary insurance that the
insured had obtained for the same policy period. (See ante, at
p. 21.) Community Redevelopment concluded that “other

41
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

insurance” provisions should operate in the same manner for
continuous injury claims that trigger multiple policy periods.
Community Redevelopment, however, failed to recognize
that cases construing “other insurance” provisions in the context
of noncontinuous injuries do not speak to the ambiguity that we
address here (which was the same ambiguity at issue in
Montrose III): are “other insurance” clauses most reasonably
construed as applying to other underlying insurance issued
during the same policy year or do such clauses extend to other
underlying insurance issued during different policy years within
the continuous period of injury? Because cases addressing
noncontinuous injury claims do not speak to this ambiguity,
Community Redevelopment erred in relying on them.13
For the reasons explained above, we disapprove
Community Redevelopment’s conclusion that standardized
“other insurance” provisions appearing in first-level excess
policies compel a rule of horizontal exhaustion. We likewise
disapprove language in Padilla Construction Co., Inc. v.
Transportation Ins. Co. (2007) 150 Cal.App.4th 984 and

13
In addition to finding that the “other insurance” provisions
compelled a rule of horizontal exhaustion, the Community
Redevelopment court believed that “a horizontal exhaustion rule
. . . is most consistent with the [all-sums] principles enunciated
in Montrose [I, supra, 10 Cal.4th 645].” (Community
Redevelopment, supra, 50 Cal.App.4th at p. 340.) However, we
rejected an essentially identical argument in Montrose III. (See
Montrose III, supra, 9 Cal.5th at pp. 235–236 [rejecting
insurers’ assertion that a “rule of horizontal exhaustion is
logically compelled by our adoption of an all-sums-with-stacking
approach to liability for long-tail injuries”; “There is no evident
inconsistency between an all sums approach and [vertical
exhaustion]”].)

42
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

Stonewall Ins. Co. v. City of Palos Verdes Estates (1996)
46 Cal.App.4th 1810, suggesting that California law generally
requires horizontal exhaustion of all primary insurance in cases
of continuous loss. (See Padilla, at pp. 986–987; Stonewall, at
pp. 1852–1853.)
2. Additional considerations regarding Truck’s
contribution claim
Montrose III was a coverage action that required us to
determine whether the insured was permitted to access its
higher-level excess policies. The answer to that question
depended entirely on our interpretation of the policies at issue
in that case. Here, however, we are faced with an equitable
contribution claim between insurers. As noted above, the terms
of the insurers’ policies comprise only one of the factors courts
may consider when evaluating whether contribution would
“ ‘accomplish ultimate justice’ ” (Signal, supra, 27 Cal.3d at
p. 369) in a particular case (see ibid.; ante, at pp. 17–18). Thus,
the fact that we have rejected the Court of Appeal’s conclusion
that the excess policies do not create any indemnity obligation
until all primary insurance has been exhausted, and instead
have interpreted those policies in a manner that would permit
the insured (Kaiser) to access the policies upon exhaustion of the
directly underlying primary policies, does not resolve whether
Truck is entitled to contribution from the excess insurers.
To that end, the excess insurers and Kaiser argue that
even if, as a matter of contract interpretation, the policies are
most reasonably construed as allowing the insured (Kaiser) to
access the first-level excess policies upon exhaustion of the
directly underlying primary insurance, it would nonetheless
remain unfair as a matter of equity to ever order an excess

43
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

insurer to contribute to a primary insurer given the distinct role
those two types of carriers play in covering a loss. Although we
have concluded that the qualitative distinctions between
primary and excess insurance do not present a sufficient basis
to depart from the interpretation of the “other insurance”
provisions that we adopted in Montrose III (i.e., that such
provisions impose only a rule of vertical exhaustion on the
insured), whether those distinctions might have more salience
in the context of equitable contribution between insurers
remains an open question. (See generally Dart, supra, 28
Cal.4th at p. 1080 [“the obligation of successive primary
insurers to cover a continuously manifesting injury is a separate
issue from the obligations of the insurers to each other”];
SantaFe, supra, 52 Cal.App.5th at p. 29 [whether a policy
requires horizontal or vertical exhaustion presents “a different
question” than determining “the rights of . . . carriers . . . to
contribution”].)
The excess insurers and Kaiser further argue that even if
there might be some circumstances where it would be
appropriate to order contribution between primary and excess
insurers, such an order would be unjust under the facts
presented in this case. They explain that because Truck agreed
to indemnify Kaiser up to $500,000 for each asbestos-related
bodily injury claim but placed no aggregate limit on coverage
(something no other primary insurer did), ordering the excess
insurers to contribute to that initial $500,000 in coverage would
effectively allow Truck to pay less coverage than it promised
under its 1974 policy. They further contend that ordering
contribution would simultaneously leave Kaiser (and asbestos
claimants) with less overall coverage by prematurely exhausting

44
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

excess insurance that could otherwise be used to cover
individual asbestos claims that exceed Truck’s $500,000 per
occurrence limit or claims that do not trigger Truck’s 1974 policy
(i.e., claims in which initial exposure occurred after the 1974
policy period). In support of these arguments, Kaiser and the
excess insurers cite expert testimony and other evidence
regarding claims allocation that was presented during the bench
trial.
Because the Court of Appeal denied contribution based
solely on its erroneous interpretation of the first-level excess
policies, it did not consider these or any other alternative
arguments related to the question of contribution. Having now
clarified that the first-level excess insurers’ indemnity
obligations to Kaiser attach upon exhaustion of the directly
underlying primary policies, we find it appropriate to remand
the matter for the court to reevaluate whether contribution
would “ ‘accomplish ultimate justice’ ” (Signal, supra, 27 Cal.3d
at p. 369) among the insurers and their policy holder. (See, e.g.,
Coast Community College Dist. v. Commission on State
Mandates (2022) 13 Cal.5th 800, 822 [remanding to allow the
court to “ ‘resolve [unexamined issues] . . . in the first
instance’ ”]; Hamilton, supra, 22 Cal.4th at p. 1149 [“It is
appropriate to remand for the Court of Appeal to resolve . . . in
the first instance” issues that the court chose “not [to] reach
because of its holdings”].)
On remand, the parties are free to raise any arguments
they believe may aid the court in deciding whether contribution
is ever appropriate between primary and excess insurers and, if
so, whether contribution would be appropriate under the
circumstances of this case. The Court of Appeal, in turn, retains

45
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

discretion to make a further remand to the trial court if it
concludes that the trial court is better positioned to address any
questions of contribution that may arise in the further
proceedings.14
III. DISPOSITION
The Court of Appeal’s judgment is reversed, and the
matter is remanded for further proceedings consistent with this
opinion.

14
Like the Court of Appeal, the trial court’s decision to deny
contribution was predicated exclusively on its finding that the
excess policies required horizontal exhaustion. (See ante, at
pp. 14–15.) As a result, the trial court did not address any of the
parties’ other arguments regarding contribution, much of which
was presented through expert testimony at trial. Thus, to the
extent the Court of Appeal concludes that Truck is potentially
eligible for contribution, it may further conclude that the trial
court is in a better position to weigh the equities at stake given
its familiarity with the parties and their relative positions in
this long-running litigation. (See Hartford Casualty Ins. Co. v.
Travelers Indemnity Co. (2003) 110 Cal.App.4th 710, 724 [“In
evaluating competing claims for equitable contribution, the trial
court exercises its discretion to weigh the equities to
‘ “ ‘accomplish ultimate justice’ ” ’ ”]; Axis, supra,
204 Cal.App.4th at p. 1228 [“in an equitable contribution action,
a court reviews the applicable facts and policies and decides
what is fair between the potential coinsurers”].) We leave those
determinations to the Court of Appeal.

46
TRUCK INSURANCE EXCHANGE v. KAISER CEMENT
AND GYPSUM CORP.
Opinion of the Court by Groban, J.

GROBAN, J.
We Concur:
GUERRERO, C. J.
CORRIGAN, J.
LIU, J.
KRUGER, J.
JENKINS, J.
EVANS, J.

47
See next page for addresses and telephone numbers for counsel who
argued in Supreme Court.

Name of Opinion Truck Insurance Exchange v. Kaiser Cement and
Gypsum Corp.
__________________________________________________________

Procedural Posture (see XX below)
Original Appeal
Original Proceeding
Review Granted (published)
Review Granted (unpublished) XX NP opn. filed 1/7/22 – 2d Dist.,
Div. 4
Rehearing Granted
__________________________________________________________

Opinion No. S273179
Date Filed: June 17, 2024
__________________________________________________________

Court: Superior
County: Los Angeles
Judge: Kenneth R. Freeman
__________________________________________________________

Counsel:

Pia Anderson Moss Hoyt, Scott R. Hoyt, Adam L. Hoyt; Greines,
Martin, Stein & Richland, Robert A. Olson, Jonathan H. Eisenman and
Edward L. Xanders for Plaintiff and Appellant.

The Cook Law Firm, Philip E. Cook and Brian J. Wright for
Defendant, Cross-complainant and Appellant Kaiser Cement and
Gypsum Corporation.

Covington & Burling, David B. Goodwin, Breanna K. Jones and Billie
T.H. Mandelbaum for United Policyholders as Amicus Curiae on behalf
of Defendant, Cross-complainant and Appellant Kaiser Cement and
Gypsum Corporation.

Morgan, Lewis & Bockius and Jeffrey S. Raskin for Santa Fe Braun,
Inc., as Amicus Curiae on behalf of Defendant, Cross-complainant and
Appellant.
Duane Morris, Brian A. Kelly, Paul J. Killion and Kathryn T.K.
Schultz for Defendant and Appellant.

Lynberg & Watkins, Sinnott, Puebla, Campagne & Curet and Wendy
E. Schultz for Cross-defendant and Appellant and Defendant and
Respondent.

Squire Patton Boggs, G. David Godwin and Tania L. Rice for
Defendant and Respondent The Continental Insurance Company.

Selman Breitman, Elizabeth M. Brockman and Calvin S. Whang for
Defendants and Respondents National Casualty Company and Sentry
Insurance a Mutual Company.

Crowell & Moring, Mark D. Plevin and Christine E. Cwiertny for
Defendants and Respondents Fireman’s Fund Insurance Company and
Allianz Underwriters Insurance Company.

Kendall Brill & Kelly, Alan Jay Weil; Shipman & Goodwin, Ruggeri
Parks Weinberg, James P. Ruggeri, Katherine M. Hance and Edward
B. Parks II for Defendant and Respondent First State Insurance
Company.

Aiwasian & Associates and Deborah A. Aiwasian for Defendant and
Respondent Westchester Fire Insurance Company.

Davis Wright Tremaine, Everett W. Jack, Jr., and Lawrence B. Burke
for Defendant and Respondent Transport Insurance Company.

Traub Lieberman Straus & Shrewsberry, Robert Dennison, Kevin P.
McNamara, Giuseppe Castaldi and Laura Siegel-Puhala for Defendant
and Respondent Evanston Insurance Company.
Counsel who argued in Supreme Court (not intended for
publication with opinion):

Robert A. Olson
Greines, Martin, Stein & Richland LLP
6420 Wilshire Boulevard, Suite 1100
Los Angeles, CA 90048
(310) 859-7811

Brian A. Kelly
Duane Morris LLP
Spear Tower, One Market Plaza, Suite 2200
San Francisco, CA 94105-1127
(415) 957-3213

Philip E. Cook
The Cook Law Firm, P.C.
601 S. Figueroa Boulevard, Suite 2050
Los Angeles, CA 90017
(213) 988-6100

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Source: Frix Law Library, https://www.frixlaw.com/law-library/cases/10034059. Public record. Not legal advice.