Liability only pays others when you are at fault (bodily injury and property damage). Full coverage is everyday shorthand for liability plus collision and comprehensive (and often UM/UIM, rental, and roadside). Lenders and lessors usually require the “full” stack until the loan is paid. This guide is a decision framework with numbers, not the older-car drop-collision deep dive (When should I drop collision on an older car).
State minimum liability is not the same as “enough.” Confirm lender requirements and your declarations page.
What each stack actually includes
| Piece | Liability-only | Typical “full coverage” |
|---|---|---|
| Bodily injury / property damage liability | Yes | Yes |
| Collision (crash damage to your car) | No | Yes, with deductible |
| Comprehensive (theft, hail, animal, fire) | No | Yes, with deductible |
| UM/UIM | Optional / state rules | Often included; verify limits |
| Rental / roadside | Usually no | Optional add-ons |
Shop apples-to-apples when pricing (Comparison-shop auto insurance). UM/UIM is separate from collision (Uninsured motorist coverage).
Number framework: premium saved vs repair risk
Use three figures:
- Annual cost of collision + comprehensive (pull from a quote that isolates those lines, or subtract a liability-only quote from a full quote on the same liability limits).
- Car’s realistic retail value (Kelley Blue Book / Edmunds-style private-party midpoint, not what you wish it were).
- Cash you can pay in 72 hours for the deductible plus a week without the car (Auto insurance deductibles; Emergency fund basics).
Rule of thumb sketch (not a statute): if annual comp+collision premiums approach 10%+ of the car’s value for several years, and you have no lender, run the drop-collision math carefully. If the car is worth $18,000 and financed, keep full coverage until the lienholder releases you.
Worked example
Riley’s 2019 Civic is worth about $12,500. Quotes on the same 100/300/100 liability:
| Stack | Six-month premium |
|---|---|
| Liability + UM/UIM only | $410 |
| Same + $500 collision/comp | $690 |
Collision+comp costs $560/year. One at-fault crash with a $4,000 repair means Riley pays $500 deductible with full coverage, or $4,000 out of pocket with liability only (plus the other party’s claim under liability either way). Riley keeps full coverage while the car is worth well above the deductible and savings are under $6,000.
Premium vs deductible: Premiums vs deductibles.
When liability-only is more reasonable
- No loan/lease requirement.
- Car value is near or below your collision deductible.
- You can replace or walk away from the car without borrowing at 20% APR.
- You still keep liability limits you would want if you hurt someone (do not cut BI/PD to “save”).
Checklist
- Confirm lienholder or lease requirements in writing.
- Price liability-only vs full on the same liability and UM/UIM limits.
- Write down annual comp+collision cost vs car value.
- Fund the deductible in cash before you choose higher deductibles.
- Revisit when the loan ends or the car’s value falls sharply.
Educational only. Not an insurance quote or lender advice. Requirements and rating vary by state, insurer, and finance contract; confirm with your declarations page, lienholder, and a licensed agent.