ALBANY — State lawmakers last week passed legislation to add a Corrections Law provision that prohibits double bunking in prison dormitories.

Introduced in January, the proposed change passed the Senate in April and the Assembly last week, drawing praise from union officials representing more than 18,000 corrections officers statewide.

Michael B. Powers, president of the New York State Correctional Officers & Police Benevolent Association, called on Gov. Andrew M. Cuomo to sign the legislation into law “immediately.”

“Forcing incarcerated individuals to be ‘double bunked’ was a necessary step decades ago when the state had to increase the capacity of its prison system, but that need no longer exists,” Mr. Powers said in a statement Tuesday. “By passing legislation prohibiting this outdated practice, the state is finally right-sizing the system with the safety and security of our staff in mind.”

The justification written into the pair of bills describes the authorization of double bunking inmates starting in the late 1980s, when the state Department of Corrections and Community Supervision was managing an “expanded prison population.” The more than 30-year-old practice increases the number of inmates housed at medium-security facilities from a typical 50 to between 60 and 90 inmates in a dorm.

As the state’s prison population has declined since that authorization, DOCCS regulations most recently allowed an additional 10 inmates to be housed in medium-security dorms designed for 50 people, with the 10 additional inmates sharing a cubicle with someone else.

When the COVID-19 pandemic struck New York, several DOCCS regulations were adjusted and prompted changes to visitation, facility cleaning and inmate spacing. Officially lowering dorm capacity in Corrections Law, according to the union, “will ensure there is no return to this practice.”

The Assembly passed the bill 148 to 1. Republican Michael A. Montesano, representing parts of Long Island, voted against the measure. All 63 state senators unanimously passed the bill on April 28.

Assemblyman D. Billy Jones, D-Plattsburgh, introduced the proposed change this year, citing 20 years of experience as a corrections officer in statements this week.

“The prison setting is stressful enough without requiring a single officer to supervise 60 inmates during a shift,” Mr. Jones said. “The practice of double bunking is irresponsible and outdated.”

He added the change is “well overdue.”

Once signed by the governor, the maximum 50 inmate dorm capacity is expected to be implemented within 90 days and will affect the state’s 27 medium-security facilities, including the eight in the north country: Cape Vincent, Gouverneur, Ogdensburg, Riverview, Bare Hill, Franklin, Altona and Adirondack.