Montana Stacking & Multiple Insurance Policies

Stacking does not create insurance

“Stacking” means combining two or more applicable insurance limits for the same loss. It becomes relevant only after at least two coverages independently protect the claimant and apply to the event.

Modern stacking analysis begins with MCA § 33-23-203

Section 33-23-203 presently establishes the starting limits rule for each part of a Montana motor-vehicle liability policy unless the policy specifically provides otherwise.

Same-company nonaggregation under subsection (1)(c)

The statute provides that limits specified under one policy or more than one policy issued by the same company may not be added together for one accident when the premiums charged:

• actuarially reflect limiting the coverage separately to the vehicles covered by the policy; and
• the applicable premium rates have been filed with the Commissioner.

Written notice is a separate statutory requirement

Section 33-23-203(3) requires an insurer charging a premium for specified coverage to clearly inform or notify the insured in writing:

• of the limits of coverage associated with the premium charged; and
• whether coverage from one policy or motor vehicle may be added to coverage from another policy or motor vehicle.

Section 33-23-203 does not itself create coverage

Subsection (4) expressly states that the section is not intended to create coverage for a motor vehicle that would otherwise be uninsured.

That statutory instruction fits Montana's case law: first determine whether coverage exists. Then determine the available limits.

Why the older Montana cases still matter

Montana's pre-2007 cases developed a strong public-policy rule against collecting valuable consideration for personal insurance protection and then using contract language to make the purchased benefit substantially illusory.

That history remains important, especially for UM, UIM and MedPay, but it must now be applied together with the current statute.

Montana's first-party stacking cases

Bennett: separate UIM policies and separately purchased protection

In Bennett v. State Farm Mutual Automobile Insurance Co., 261 Mont. 386, 862 P.2d 1146 (1993), the insured was injured as a pedestrian and sought UIM protection under two separate State Farm policies.

Montana treated the UIM coverage before the Court as personal protection and refused to enforce the anti-stacking limitation in a manner that denied the separately purchased benefit.

Ruckdaschel: the same principle applied to MedPay

In Ruckdaschel v. State Farm Mutual Automobile Insurance Co., 285 Mont. 395, 948 P.2d 700 (1997), the claimant was injured as a pedestrian and had three separate policies that each independently provided applicable medical-payments coverage.

Separate premiums had been paid for each applicable MedPay coverage. The Montana Supreme Court rejected State Farm's anti-stacking limitation under the public policy then governing the policies.

Dakota Fire v. Oie: separately paid UM protection

Dakota Fire Insurance Co. v. Oie, 1998 MT 288, 292 Mont. 486, 971 P.2d 1202, continued the same historical principle where named insureds paid separate premiums for separate UM coverage.

Lierboe: no second coverage means nothing to stack

In Lierboe v. State Farm Mutual Automobile Insurance Co., 2003 MT 174, 316 Mont. 382, 73 P.3d 800, the claimant sought to combine MedPay under another policy.

The second policy did not independently cover her loss under its insured and vehicle provisions. The Montana Supreme Court therefore characterized the case as a coverage case rather than a stacking case.

Hardy: the landmark pre-2007 UIM decision

Hardy v. Progressive Specialty Insurance Co., 2003 MT 85, 315 Mont. 107, 67 P.3d 892, involved three $50,000 UIM coverages and three separate premiums.

The Montana Supreme Court rejected the policy and statutory structure then before it because the insurer had received valuable consideration while using the coverage structure to withhold the protection represented by those purchases.

Gibson: coverage before aggregation

State Farm Mutual Automobile Insurance Co. v. Gibson, 2007 MT 153, 337 Mont. 509, 163 P.3d 387, revisited Montana's first-party MedPay cases and emphasized the analytical sequence:

1. determine whether the policy provides the coverage;
2. determine whether the claimant is an insured under that coverage;
3. determine whether the loss falls within that coverage; and
4. only then determine whether an anti-stacking limitation controls.

Post-amendment Montana cases refine the rule

LaMere: settlement finality and the older statutory period

LaMere v. Farmers Insurance Exchange, 2011 MT 272, arose from a 2001 accident and a UM settlement executed under the pre-Hardy statutory regime.

The Montana Supreme Court refused to reopen the settled claim and did not use Hardy to undo a final release. LaMere is useful because it shows that stacking law cannot be separated from the policy period, governing statutory version and settlement finality.

Parish: two vehicles did not produce two UM limits

In Parish v. United Financial Casualty, 2012 MT 116, the policy covered two vehicles but the insureds paid one UM premium that remained the same whether the policy insured one or two vehicles.

The policy unambiguously prohibited stacking, and the Montana Supreme Court affirmed the single-limit result under the post-2007 framework.

First-party stacking and third-party liability limits are different

Montana's strongest stacking cases developed around benefits purchased for and payable to insured persons:

Cross v. Warren: do not automatically stack another person's liability limits

In Cross v. Warren, 2019 MT 51, 395 Mont. 62, 435 P.3d 1202, injured third-party claimants sought to combine liability limits assigned to four vehicles insured under the defendants' Progressive automobile program.

The Montana Supreme Court affirmed denial of the requested liability stacking. The Court distinguished Montana's personal-and-portable first-party coverage cases from a third-party claimant's attempt to aggregate another insured's liability limits.

Recent persuasive federal application: Lohrke

In Lohrke v. American Family Connect Insurance Agency, Inc., a 2025 federal district-court decision applying Montana law, the insured paid separate per-vehicle premiums for UM and MedPay on three vehicles.

On the record before it, the District of Montana concluded that the UM and MedPay coverages stacked notwithstanding anti-stacking language. The court relied on Montana's paid-for-coverage decisions, current § 33-23-203, and later applications of Parish.

Lohrke is also a useful reminder that a separate-premium record can remain highly important even after the 2007 amendment. The analysis still requires the actual policy, premium structure, statutory compliance and controlling Montana authority.

Montana stacking workflow

A reliable stacking analysis begins with the insurance architecture, not with the number of vehicles displayed on the declarations page.

Documents to obtain

• every potentially applicable policy
• every declarations page
• all endorsements
• all insured vehicles
• policy effective dates
• UM limits
• UIM limits
• MedPay limits
• liability limits
• complete premium breakdown
• billing history
• renewal declarations
• anti-stacking provisions
• other-insurance clauses
• offset provisions
• anti-duplication provisions
• coverage definitions
• insured definitions
• covered-auto definitions
• written § 33-23-203 notice
• rate-filing information when material
• actuarial premium support when material
• applications
• coverage-selection forms
• coverage correspondence
• claim-payment history
• prior settlement or release documents

Common stacking mistakes

• Counting vehicles and assuming each creates another limit.
• Counting premiums without determining what each premium purchased.
• Assuming separate premiums automatically answer the modern statutory question.
• Assuming clear anti-stacking wording automatically ends the analysis.
• Skipping insured-status analysis.
• Trying to stack a policy that does not cover the loss.
• Confusing a coverage exclusion with an anti-stacking provision.
• Applying Hardy without current § 33-23-203.
• Ignoring written aggregation notices.
• Ignoring actuarial premium treatment where subsection (1)(c) matters.
• Ignoring filed rate requirements.
• Applying first-party stacking cases automatically to liability limits.
• Failing to distinguish same-company policies from policies issued by different insurers.
• Assuming a federal Montana decision is controlling state precedent.
• Using the wrong statutory version for the policy period or accident.

Montana authority map