By 1921, the Eastern New York Reformatory had evolved into a dumping ground for recidivists, parole violators, and "incorrigibles." It had been blasted by the State Commission of Prisons as "simply a prison, and a poor one," unworthy of the reformatory name.

Surprisingly, it was only after the legislature relieved Napanoch of any reformative purpose -- when it was designated as a custodial institution for defectives who were felt to be "unreformable" by definition -- that it would begin to achieve reformatory goals. For most of the 45 years that the institution held mental defectives, its administration and staff made sincere efforts to improve the functioning of its inmates. After an initial period of adjustment, Napanoch would exceed the expectations of its founders and offer an effective educational and social training program.

On June 6, 1921, 58 retarded men from Rome State School became the IDD's first inmates. They were joined in the coming days by other transfers from state schools and also from the state prisons.