California corrections officials say they are adopting new sentencing rules that aim to trim the state prison population by nearly 9,500 inmates after four years.

The regulations released Friday include steps like reducing sentences up to six months for earning a college degree and by up to a month each year for participating in self-help programs like drug counseling.

The changes eventually lower the prison population by about 7 percent.

Corrections Secretary Scott Kernan tells The Associated Press he expects the changes eventually will let California end long-running federal lawsuits targeting prison overcrowding and inadequate health care for inmates.

The changes follow voters' approval of Proposition 57 in November. The initiative lets felons seek parole more quickly and gave corrections officials broad discretion to grant early release credits.