From the USAC website...

Qualifying Distances for each category

To qualify for upgrading points, races must meet distance standards. Races shorter than the minimum distance do not qualify for upgrading. However, if a road race is less than the road race minimum but above the criterium minimum, it will count for upgrading using the criterium points schedule.

Category Class RR Criterium and Circuit

5 – 4 Men 15 mi 10 mi

4 – 3 Men 25 mi 20 mi
Women 25 mi 15 mi
Junior 25 mi 15 mi

3 – 2 Men 50 mi 20 mi
Women 40 mi 15 mi

2 – 1 Men 80 mi 30 mi
Women 50 mi 20 mi