City lawmakers are set to probe how an embattled city agency allowed thousands of apartments meant for homeless New Yorkers to sit empty as the Big Apple’s homelessness crisis exploded into full view in recent months.

The hearing is set for May 3.

The Post first revealed that the Human Resources Administration allowed the 2,500 city-funded apartments to go unused because of bureaucratic dysfunction, short-staffing and a cumbersome application system in March, a fiasco that Mayor Eric Adams quickly pledged to fix.

But over the intervening month, just 200 of the apartments had been filled and advocates for the homeless said they had seen little change at opaque social services provider.

“Fixing this failure to place people in open supportive housing units is an issue the Council’s General Welfare Committee will be looking to question city agency officials on at its upcoming hearing,” said a Council source.