His Majesty's Young Offender Institution

His Majesty's Young Offenders Institution (Her Majesty's Youth Offenders Institution if the reigning monarch is female) (or HM YOI) are youth detention centres for offenders between ages 15 to 21 in the United Kingdom. These offenders will have received a custodial sentence following criminal offence convictions or may be being held on remand awaiting trial on pending charges.

A young offender's institution can accommodate between 60 and 400 young people, with each age group housed in its own wing of between 30 and 60 inmates. Most young offenders' institutions are run by the national prison service while some are run by private companies on behalf of the prison service.

Background
Young Offender Institutions were introduced under the Criminal Justice Act 1988, but secure institutions specifically intended for young offenders have existed since the beginning of the 20th century: the first borstal opened at Borstal, Kent in 1902.

The regime of a Young Offender Institution is similar to that of an adult prison. There are slight differences, notably a lower staff-to-offender ratio. Prisoners serving sentences at Young Offender Institutions are expected to participate in at least 25 hours of education per week, aimed at behaviour improvement, practical skill development for post-release and employment preparation. There are also opportunities for prisoners to undertake work in Community Service Volunteer programmes.

Issues
Violence is frequently reported in Young Offender Institutions and staff have been criticised for failing to prevent it. Solitary confinement is often used, with inmates reportedly often confined to cells for up to 21 hours a day and given little tuition or guidance. At all YOIs during a six-month period there were 306 cases of segregation lasting over a week, which is "very high", with contributory factors including gang involvement, insufficient prison staff and a lack of NHS mental health beds.

Recidivism rates are high, with up to three quarters of released offenders re-offending within a year. Offenders undergo assessments on the likeliness of reoffending. This assessment is known as Youth level of service.

List of Young Offender Institutions

 * HMP & YOI Askham Grange
 * HMP & YOI Brinsford
 * HMP & YOI Bronzefield
 * HMP & YOI Chelmsford
 * HMYOI Cookham Wood
 * HMP & YOI Deerbolt
 * HMP & YOI Drake Hall
 * HMP & YOI East Sutton Park
 * HMP & YOI Eastwood Park
 * HMYOI Feltham
 * HMP & YOI Foston Hall
 * HMP & YOI Hatfield
 * HMP & YOI High Down
 * HMP & YOI Hindley
 * HMP & YOI Hollesley Bay
 * HMP & YOI Hull
 * HMP & YOI Isis
 * HMP & YOI Lincoln
 * HMP & YOI Low Newton
 * HMP & YOI Moorland
 * HMP & YOI New Hall
 * HMP & YOI Norwich
 * HMP & YOI Parc
 * HMP & YOI Pentonville
 * HMYOI Polmont
 * HMP & YOI Portland
 * HMP & YOI Prescoed
 * HMP & YOI Rochester
 * HMP & YOI Stoke Heath
 * HMP & YOI Styal
 * HMP & YOI Swinfen Hall
 * HMP & YOI Thorn Cross
 * HMYOI Werrington
 * HMYOI Wetherby
 * HMP & YOI Winchester
 * HMP & YOI Woodhill