Chief Constable Sir Hugh Orde has said he "broadly supports" the latest report on IRA activity by the Independent Monitoring Commission.
Hugh Orde has addressed a meeting of the Policing Board
The report said the IRA had changed radically and some of its most important structures were dismantled.
Sir Hugh told the Policing Board the trends are the IRA is winding down.
However, he said there was a "grey area" over whether IRA members engaged in crime were doing so on behalf of the organisation or for personal gain.
"I have no evidence to suggest they (Provisional IRA) have any intention of going back to an armed struggle in any way shape or form in terms of activities," he said.
"The grey area, as ever, will be activities undertaken by people who are members of the Provisional IRA which we would class as criminal.
"And the question as always is, was that for the organisation or was that for the individual? But in broad terms I accept what the IMC was saying."
The Policing Board holds the PSNI to account
The Policing Board, which met in Belfast, also heard that sick leave cost the police service £30m in lost days over the past 18 months.
The vast majority of that sum, more than £23m, was due to the sickness of police officers, while the rest was down to civilian staff.
Established on 4 November 2001, the Policing Board holds the PSNI to account.
Sinn Fein has resisted giving the PSNI, the Policing Board and other institutions its support, insisting more legislation is needed before it can sign up.
The party said it needed to see more power transferred to local politicians before it would consider nominating representatives.
The two governments have given the politicians until 24 November to reach a deal on devolution.
The DUP is still demanding Sinn Fein fully support the police before they consider any agreement.