General Concepts

Stacking

Stacking allows policyholders to add together the limits of separate policies or separate vehicles on the same policy to create a larger pool of coverage for a single loss.

Last reviewed: May 2026 · Editorial methodology

Definition

Stacking most commonly arises in uninsured/underinsured motorist coverage: if you own two cars each with $100,000 UM/UIM limits, stacking lets you access $200,000 for one accident. It also appears in multi-policy scenarios — for example, stacking a primary liability policy with an umbrella. Whether stacking is permitted depends on state law and policy language; many policies include anti-stacking provisions, and some states prohibit inter-policy stacking while permitting intra-policy stacking. Stacking can dramatically improve recovery in serious injury cases where a single policy limit is insufficient. If your insurer offers a non-stacking policy at a discount, carefully weigh the savings against the reduced ceiling — especially if you have multiple household drivers.

Where this term matters

Auto Insurance →Umbrella Insurance →Home Insurance →

Tip

Glossary definitions are educational. Always check your own policy language — insurers can define common terms differently from one another. When in doubt, request a written explanation from your agent.

Related terms

Umbrella PolicyExcess personal liability coverage above auto/home/boat limits — starts at $1M for $150–$400/year.Combined Single Limit (CSL)A single dollar cap covering both bodily injury and property damage liability in one combined amount.Per-Occurrence LimitA per-occurrence limit defines the ceiling on what your policy pays out for one distinct incident, separate from the annual aggregate cap.Policy Aggregate LimitThe aggregate limit caps your insurer's total payout across all losses in the policy term, regardless of how many separate incidents occur.
Source: Cover Forge USA editorial team|Last verified: May 2026|Methodology
Definitions are educational and may be simplified. Always refer to your policy contract and consult a licensed agent for terms that affect coverage decisions.
CF

Cover Forge USA Editorial Team

Editorial Lead

This article was researched and written by the Cover Forge USA editorial team against federal sources (NAIC, CMS, FEMA, DOL, SSA, state DOIs) and standard policy forms. Bylines organize content by topic — they do not assert individual licensure. See our editorial-policy for details.

Reviewed June 2026

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