Uninsured motorist insurance
Uninsured motorist insurance means insurance under which the policyholder's insurer will pay for damages caused by a motorist who has no automobile liability insurance or who carries less than the amount of insurance required by law, or is underinsured.
42 CFR § 411.50
Limits on applicability. The provisions of this subpart C do not apply to any services required because of accidents that occurred before December 5, 1980.