New Yorkers are paying about 23 percent more for state prisons than the state corrections budget actually reflects, according to a new study by the Vera Institute of Justice, a criminal justice research organization.

Taxpayers fork over about $3.6 billion to fund prisons, but the state corrections budget only sets aside $2.7 billion, according to the study.

Michael Jacobson, who directs the Vera Institute, said the findings should remind states to look outside their corrections budgets if they want to cut prison costs.

"There's so much attention to prisons now and trying to save money, so we want to encourage states, intelligently, to take a look at it, because the savings opportunities are, obviously, huge," Jacobson said.

The study found most of the prison costs falling outside the corrections budget are for healthcare and pension contributions.  It calculates that New York made of contribution of $179.5 million for corrections employees in 2010 and paid $223.9 million in healthcare contributions that year.

"The good news is, if you can shrink your system to some extent, you'll actually save more than you think you will," Jacobson said.

Governor Andrew Cuomo has proposed cutting pension benefits for new state worker hires, but the unions oppose the idea.

According to the Vera study, New York ranks among the top six states for the highest percentage of prison costs lying outside the corrections budget. 

New York's prison population has fallen 23 percent since its peak in 1999 of more than 71,000 inmates.

The state Department of Corrections declined to comment on the study.