Accident Forgiveness

Accident forgiveness is an option, typically at additional cost, in your coverage.

As the phrase implies, based on the carrier, you are forgiven for an at-fault or partially at-fault accident.  Some carriers offer this after a set period of renewals (3-6 years), but most offer it for an additional cost and is effective immediately.  

Most forgive ONE accident (and some ONE violation / ticket) every three years. 

It basically guarantees your rate will not be raised based on the accident, but this will not carry over to a new carrier should you move your insurance.