SR-22

An SR-22 is an administrative form that attests to an insurance company's coverage, or the posting of a personal public bond in the amount of the state's minimum liability coverage for the licensed driver/ or vehicle registration. SR-22s are typically filed with the respective State's DMV, and in some States must be carried by the licensed driver, or in the registered vehicle (particularly if the licensee has been cited for coverage lapses, DUI or other administrative infractions). SR-22s may attest coverage for a vehicle regardless of operator (owner liability coverage), or cover a specific person regardless of the specific vehicle operated (operator liability coverage).
The form is required in 49 States and the US District of Columbia in order to register a vehicle for usage on public roads (with the notable exception being New Hampshire). It is also required to redeem a license which has been suspended due to coverage lapse in these required States. These States also, generally, require that the issuing insurance company provide the relevant State's DMV with timely updates as to the status of such coverage. (e.g. expiration/cancellations)