The Government's ambitious goal of reducing reoffending by 25 per cent is so ingrained in the Corrections system that prisoners are repeating it back to officials, Corrections Minister Anne Tolley says.

An Auditor-General's review of the Corrections Department's efforts to reduce reoffending has praised its overall strategy and individual programmes, in particular the extension of rehabilitation to offenders serving short sentences.

Its reoffending policies were not without flaws, and the Auditor-General made recommendations such as ensuring that rehabilitation did not lapse once inmates had finished programmes and better management of offenders' release into the community.

As part of the Government's goals for the public sector, Corrections was aiming to reduce the rate at which prisoners reoffended within a year of release by 25 per cent before 2017.

Corrections Minister Anne Tolley said the ambitious goal had penetrated from officials at the top through to inmates, who had discussed it with the Auditor-General's office during the review.

The report said the target had "struck the hearts and minds of staff" and encouraged them to innovate, because a "business as usual" approach would not allow them to reach the goal.

The Auditor-General said Corrections had a strong emphasis on evidence-based policy such as its focus on education and drug and alcohol programmes to cut offending.

The department was targeting groups which contributed disproportionately to the rates of reoffending - remand prisoners, young people, Maori, and those with alcohol or drug problems.

About 6000 prisoners serving sentences of two to three years were released each year. This group had the highest reoffending rates, but did not usually qualify for rehab programmes. After a pilot programme showed the value in targeting rehab to remand and short-stay prisoners, this approach was now being rolled out to all New Zealand prisons.

The review expressed some concern about Corrections' scheduling systems, which often led to an offender being relocated to a mainstream unit after a rehab programme. This often meant the inmate lost skills they had learned.

Mrs Tolley said the department was addressing this problem by giving prisoners structured, eight-hour working days. Three of New Zealand's jails had become "working prisons" and eventually inmates in facilities nationwide would work, train or study in 40-hour weeks.

The report also recommended better management of prisoners in moving from jail to the community.

Corrections' crusade

Goal: Reduce reoffending by 25 per cent by 2017*
Progress: 11.4 per cent reduction to December 2013
*from a June 2011 baseline