Supplemental Liability Insurance
Additional liability coverage above the basic insurance included in an RV rental. Covers damage you cause to other people and property beyond the base policy.
Also called: supplemental liability, SLI, additional liability, third-party liability
Supplemental liability insurance (SLI) is additional liability coverage above the basic insurance included in an RV rental. It covers damage you cause to other people and property beyond what the base policy covers.
What’s included by default vs. SLI
Most rentals include some baseline liability — typically state-minimum coverage, which varies but is often only $25,000-$50,000 per accident.
SLI tops this up to $300,000 to $1,000,000+ in liability coverage.
Why this matters
An RV accident with serious injuries can easily generate claims exceeding $200,000. State-minimum coverage gets exhausted, and the remaining liability falls to you personally.
For renters with significant assets (home equity, retirement accounts, savings) at risk in a lawsuit, SLI is real protection.
Cost
Typically $10-$20/day for SLI on a rental.
How it interacts with personal auto
Personal auto insurance typically doesn’t extend to RV rentals. SLI is the practical way to get adequate liability coverage during the rental.
Some umbrella personal liability policies cover RV rentals — verify with your insurer. If yours does, SLI is redundant.
What SLI doesn’t cover
- Damage to the RV itself (covered by damage waiver)
- Your personal belongings
- Medical expenses for passengers in your RV (separate coverage)
- Damage during prohibited activities
When SLI matters most
- Multi-week trips — extended exposure window
- Trips with significant highway driving — accident probability scales with miles
- First-time renters — accident probability higher with limited experience
- Renters with significant assets — protecting them from lawsuit exposure
See our RV rental insurance guide for the broader insurance picture.