The Patrick administration is predicting that Massachusetts will need space for an additional 10,000 inmates by the end of the decade.
A prison master plan released by the administration Thursday calls for construction of new jails and prisons — but also for reductions in sentences.
The state Public Safety secretary, Mary Beth Heffernan, says both approaches are essential.
"We can't build our way out of a $2 billion problem," she said. "We need to handle the fact that we have aging facilities, we have an aging prison population, that we have a sicker prison population."
The plan also calls for building two or three assisted-living centers for the increasing number of older inmates with medical problems.
Heffernan says that the new facilities can be paid for by changing mandatory sentence laws for drug offenders.
"We need to change the way we deal with non-violent drug offenders, but we also need to make sure that habitual violent felons are kept in prison for the time that they need to be there," she said.
The expected cost of the plan is $550 million.
This program aired on January 19, 2012. The audio for this program is not available.