AUGUSTA – Two independent auditors have wrapped up an inspection of the Charleston Correctional Facility, the sixth state correctional facility to undergo a review as the last step toward national accreditation, officials said Tuesday.

The auditors visited the Charleston facility last week. The American Correctional Association will make a final decision on accreditation at its winter meeting, said Denise Lord, spokeswoman for the Department of Corrections in Augusta.

Five other Maine facilities already received accreditation, and the Charleston facility is expected to become the sixth, Lord said.

The state doesn’t plan to seek accreditation for two remaining facilities: the Downeast Correctional Facility in Machiasport and the Central Maine Pre-Release Center in Hallowell, Lord said. The physical plants of those facilities are too outdated, she said.

Only seven states have corrections systems that are completely accredited: New York, Massachusetts, Tennessee, Ohio, Louisiana, Nebraska and Florida. Maine will approach that status with about 85 percent of its prison population in accredited facilities.

The accreditation efforts mark a dramatic turnaround.

In 1990, the state’s corrections system was the nation’s ninth-most overcrowded. And the human rights group Amnesty International threatened a lawsuit.

In 1998, then-Gov. Angus King proposed a phased-in overhaul that combined surplus cash with long-term borrowing. Of the roughly $153 million ultimately spent, more than half went to construction of the new Maine State Prison in Warren.