Governor Brown's administration and attorneys representing inmates have failed to reach an agreement on the best way to reduce overcrowding in California prisons.
That leaves it to a panel of federal judges to decide whether to give the state more time.
The judges said in a two-paragraph statement issued Monday that they will decide within 30 days whether to stick with their current order that the state reduce the population to about 110,000 inmates.
California remains about 4,000 inmates over that level and had been given until April 18 to meet the cap.
That deadline was extended as both sides were given time to file written arguments, due by Jan. 28.