Massachusetts Correctional Institution – Shirley is a medium-security state prison in Shirley, Massachusetts. The facility also contains a minimum-security section which houses less dangerous prisoners. MCI-Shirley maintains 13 inmate housing units, a 28-bed full-service hospital unit, a 59-bed segregation unit, gym, recreation areas, school, industries, laundry, vocational area, and food services/programs. This facility is under the jurisdiction of the Massachusetts Department of Correction. It is located directly to the north of the Souza-Baranowski Correctional Center, a maximum-security facility in the town of Lancaster. On January 6, 2020 there was 992 Medium and 269 minimum inmates in general population beds.