Date: Apr 4, 2026

Anti-Stacking in Illinois UIM Coverage Caps Recovery at the Highest Single-Policy Limit, Even for Multiple Insureds in One Accident

Introduction

Thomas Polk v. Progressive Northern Insurance Company is a Seventh Circuit insurance-coverage dispute applying Illinois law to underinsured motorist (UIM) policies after a roadside tragedy. While assisting another motorist, Thomas T.D. Polk and his wife, Katarzyna Kurek-Polk, were struck by an oncoming vehicle; Thomas was injured and Katarzyna was killed. The tortfeasor paid $100,000.

Polk then sought UIM benefits under three policies in force: a $1,000,000 AMCO policy, and two $500,000 policies issued by Progressive and Secura. Each policy contained (i) a proportionate liability clause allocating payment responsibility pro rata among available UIM coverages (agreed shares: 50% AMCO; 25% Secura; 25% Progressive), and (ii) an “Other Insurance” anti-stacking clause limiting total recovery to the highest single applicable limit (here, AMCO’s $1,000,000).

Polk obtained $800,000 in a settlement with AMCO and rejected Secura’s $220,000 offer. Progressive paid nothing. Polk sued Progressive and Secura for breach of contract, arguing he could effectively “stack” limits and obtain additional payments from each carrier. The district court granted summary judgment to the insurers, capping total UIM recovery at $1,000,000 and ordering Secura to pay $100,000 to reach that cap. Polk appealed.

Key issues: (1) whether Illinois law (and the policy language) permits stacking UIM limits when two insureds are harmed in a single accident; (2) whether payments from AMCO may be used to reduce/offset what is owed by Secura and Progressive under “Other Insurance” language; and (3) the effect of proportionate-liability clauses when an anti-stacking cap applies.

Summary of the Opinion

The Seventh Circuit affirmed. It held that the anti-stacking provisions in the Progressive and Secura policies were clear and unambiguous and, combined with the pro rata provisions, capped each of Progressive’s and Secura’s maximum exposure at $250,000 (25% of the $1,000,000 highest single-policy limit), for the single accident, even though two insureds were involved.

Because Polk already received $100,000 (tortfeasor) + $800,000 (AMCO) = $900,000, only $100,000 remained to reach the $1,000,000 cap. The court rejected Polk’s arguments that (i) stacking should be allowed due to alleged ambiguity or statutory wording, and (ii) AMCO’s settlement could not reduce what Progressive and Secura owed. The court also noted that Secura’s complaint about being assigned the full $100,000 payment could not be considered absent a cross-appeal.

Analysis

Precedents Cited

Cent. States, Se. and Sw. Areas Pension Fund v. Univar Sols. USA Inc., 148 F.4th 426 (7th Cir. 2025)
Cited for the proposition that appellate review of cross-motions for summary judgment is de novo. It supplies the procedural lens for the court’s analysis, not the coverage rule itself.
Gills v. Hamilton, 164 F.4th 640 (7th Cir. 2026)
Provides the standard that, when assessing the insurers’ motions, facts and inferences are viewed in the light most favorable to the nonmovant (here, Polk).
Rahimzadeh v. Ace Am. Ins. Co., 142 F.4th 972 (7th Cir. 2025)
Supports the general choice-of-law framing that insurance policy interpretation is governed by state law, leading the panel to apply Illinois interpretive rules.
Thounsavath v. State Farm Mut. Auto. Ins. Co., 104 N.E.3d 1239 (Ill. 2018)
Used to ground two core contract principles: insurance policies are contracts; and clear, unambiguous terms are enforced as written unless they violate public policy. This anchors the court’s refusal to rewrite “Other Insurance” clauses based on Polk’s preferred result.
Kuhn v. Owners Ins. Co., 241 N.E.3d 397 (Ill. 2024)
Cited for (i) construing an insurance policy as a whole and giving effect to each provision where possible, and (ii) the Illinois ambiguity standard (susceptible to more than one reasonable interpretation). The court relied on Kuhn to reject Polk’s claimed ambiguity and to harmonize the pro rata and anti-stacking provisions.
Menke v. Country Mut. Ins. Co., 401 N.E.2d 539 (Ill. 1980); Bruder v. Country Mut. Ins. Co., 620 N.E.2d 355 (Ill. 1993); Willison v. Econ. Fire & Cas. Co., 690 N.E.2d 1073 (Ill. App. Ct. 1998)
This trilogy is the court’s primary Illinois authority for treating similar anti-stacking provisions as unambiguous and enforceable. By invoking these cases, the Seventh Circuit positioned Polk’s argument as contrary to settled Illinois treatment of broadly phrased “Other Insurance” limitations.
Grzeszczak v. Ill. Farmers Ins. Co., 659 N.E.2d 952 (Ill. 1995)
Central to two points: (i) the purpose of UIM coverage is “to fill the gap” between the tortfeasor’s coverage and what the insured purchased, not to create a multi-policy windfall; and (ii) the “premium rule of construction” does not overcome clear anti-stacking language. The court used Grzeszczak to answer Polk’s fairness argument about paying multiple premiums.
Lewert v. P.F. Chang's China Bistro, Inc., 819 F.3d 963 (7th Cir. 2016)
Cited for the appellate practice rule that a party seeking to alter the judgment must file a cross-appeal. This foreclosed Secura’s attempt to reallocate the district court’s $100,000 payment order without having appealed it.

Legal Reasoning

Anti-stacking language controlled, and it was not ambiguous.
Progressive’s clause capped the combined recovery under multiple policies to “the highest limit of liability under any one policy.” Secura’s clause likewise limited recovery to “the highest applicable limits for any one vehicle under this or any other insurance.” The court treated both as broad, straightforward anti-stacking terms, consistent with Menke, Bruder, and Willison.
Illinois statute authorizes (rather than undermines) these caps.
The court relied on the Illinois Insurance Code’s express permission for anti-stacking provisions, 215 Ill. Comp. Stat. 5/143a-2(5). Polk argued the statute’s singular “insured” implied stacking should be allowed when multiple insureds are injured in one accident. The court rejected that reading and noted Polk offered no Illinois authority adopting it. The statute was treated as confirming that Illinois permits insurers to prevent limits from increasing due to multiple coverages/vehicles.
Pro rata sharing applied only within the anti-stacking cap.
The parties agreed to 50/25/25 pro rata shares. But the court applied those shares to the maximum recoverable amount after anti-stacking: the highest single-policy limit of $1,000,000. That yielded each $500k carrier’s maximum share as $250,000.
Setoff by AMCO’s payment was inherent in the “Other Insurance” limit.
Polk argued the district court improperly offset Progressive/Secura obligations using AMCO’s $800,000 settlement. The court reasoned there was no improper “offset” separate from the contract: because total recovery was capped at $1,000,000, amounts already received from the tortfeasor and AMCO necessarily reduced what could still be collected without exceeding the cap.
Secura’s attempt to change the allocation failed without a cross-appeal.
Even if Secura had a good argument that Progressive should share the remaining $100,000, the Seventh Circuit declined review because Secura did not cross-appeal, applying Lewert.

Impact

Reinforcement of broad anti-stacking enforcement under Illinois law.
The decision underscores that when “Other Insurance” provisions clearly cap recovery at the highest single applicable limit, courts will enforce that cap even in sympathetic, multi-claimant tragedies and even when multiple insureds were harmed in the same accident.
Clarification that multiple insureds do not, by themselves, defeat a per-accident anti-stacking cap.
By rejecting Polk’s statutory-grammar argument, the opinion signals that litigants should not expect stacking merely because more than one insured suffered injury/death in the accident.
Practical consequences for multi-policy UIM claims handling.
Where pro rata clauses exist alongside anti-stacking caps, carriers’ exposures may be computed as a share of the capped maximum, and payments by one carrier (or the tortfeasor) will reduce the remaining room under the cap.
Appellate practice reminder.
Insurers (and insureds) disputing the district court’s allocation of payment responsibility must preserve the issue via a cross-appeal if they seek to change the judgment.

Complex Concepts Simplified

Underinsured Motorist (UIM) Coverage: Coverage that pays when the at-fault driver’s liability insurance is insufficient to cover the insured’s damages, subject to the UIM policy’s limits and terms.
Stacking / Anti-Stacking: “Stacking” means adding together limits from multiple policies (or coverages) to increase the maximum payable. “Anti-stacking” clauses prevent that by capping recovery—here, at the highest single policy limit.
Other Insurance Clause: A contract provision explaining how a policy interacts with other available insurance. In this case, it functioned as an anti-stacking cap (“the maximum…shall be the highest limit…under any one policy”).
Proportionate Liability (Pro Rata Share): A term that divides responsibility among multiple insurers. Here, even though Progressive and Secura each had $500,000 limits, their share was 25% each—applied to the capped maximum.
Setoff: A reduction in what is still payable because money has already been received from another source. The court treated the “setoff” as a natural consequence of the anti-stacking cap: once $900,000 had been collected, only $100,000 remained before hitting the $1,000,000 ceiling.
Premium Rule of Construction: An interpretive idea that insurers should not collect premiums for coverage and then use limitations to negate it. Illinois limits this principle: under Grzeszczak v. Ill. Farmers Ins. Co., clear anti-stacking language still governs even if multiple premiums were paid.
Cross-Appeal: A separate appeal filed by the appellee to change the judgment. Without it, an appellee generally cannot seek to improve its position on appeal (here, Secura could not challenge being assigned the full $100,000 payment).

Conclusion

The Seventh Circuit’s decision confirms that, under Illinois law, clear anti-stacking “Other Insurance” provisions cap total UIM recovery at the highest single-policy limit, and that cap applies even when multiple insureds suffer injury or death in the same accident. Pro rata sharing among insurers operates within that cap, and payments already received from the tortfeasor and another insurer reduce what remains payable to avoid exceeding the maximum. Finally, the opinion highlights a procedural safeguard: a party seeking to reallocate payment responsibility must file a cross-appeal.