The Northern Ireland Executive's voluntary exit scheme opened in 2015.
The spending watchdog has reported that 4,383 posts were axed in year one, with more than half the redundancies within the Civil Service.
While redundancy payments to staff totalled £171m, the report said they will result in annual savings of £155m.
The average cost of compensation ranged from £16,000 in NI Water to £58,000 in Libraries NI.
Auditor General Kieran Donnelly said the Department of Finance ran the scheme "in a way which was consistent with value for money".
However he added that over time "it will be important to demonstrate" savings have been sustained.
Mr Donnelly also said the scheme should be monitored going forward, so as not to have "a negative impact on staff skills, morale and service delivery".
The Northern Ireland Executive intends borrowing up to £700m over four years to reduce the size and cost of the local public sector.
The Audit Office said it was "a significant achievement" to deliver the cuts so quickly.
Stormont needs to monitor the impact of job cuts on staff morale in the public sector, a report by the NI Audit Office has recommended.