Even though both sides say they are dedicated to a sweeping reform effort, there are still significant obstacles.

Almost two years ago, the state agreed to an interim settlement that eliminated the use of solitary confinement for pregnant women, most developmentally disabled inmates and any prisoner under age 18.

And yet during that time, the number of inmates in solitary confinement has increased. Officials attributed the rise in part to the escape in June, which prompted a crackdown throughout the prison system. More than 50 people have been in solitary confinement for longer than five years. At the same time, the average length of stay in isolation has gone down, to 190 days as of December from 225 days last year.

Another major question is whether the corrections officers’ union, which has great power in the prisons, will go along with the settlement. After the interim settlement was adopted in 2014, the union filed a lawsuit, which is still pending, challenging many of the new policies.

Officials with the corrections officers’ union said they had not been included in the negotiations nor had they yet reviewed the details of the settlement. “Our state’s disciplinary confinement policies have evolved over decades of experience, and it is simply wrong to unilaterally take the tools away from law enforcement officers who face dangerous situations on a daily basis,” the union said in a written statement.

The settlement agreement, which also involved the law firm Morrison & Foerster and Alex Reinert, a professor from Cardozo Law School, must still be approved by the judge in the case, Shira A. Scheindlin, of Federal District Court in Manhattan.

Image A Nutraloaf from a prison cafeteria, similar to the one that the agreement will prohibit for inmates in solitary confinement. Credit... Andy Duback/Associated Press

The agreement establishes a maximum sentence of three months for most disciplinary violations, except assaults, and 30 days for almost any prisoner who has committed a nonviolent infraction for the first time. Isolation will no longer be imposed for first-time violations for drug use or possession, which in the past accounted for as much as one-fifth of the solitary population.