(1) Except as provided in ORS § 137.635, 137.700, 137.707, 163.105, 163.107 and 163.115, each adult in custody sentenced to the custody of the Department of Corrections for felonies committed on or after November 1, 1989, is eligible for a reduction in the term of incarceration for:

(a) Appropriate institutional behavior, as defined by rule of the Department of Corrections; and

(b) Participation in the adult basic skills development program described in ORS § 421.084.

(2) The maximum amount of time credits earned for appropriate institutional behavior or for participation in the adult basic skills development program described in ORS § 421.084 may not exceed 20 percent of the total term of incarceration in a Department of Corrections institution.

(3) The time credits may not be used to shorten the term of actual prison confinement to less than six months.

(4) The department shall adopt rules pursuant to the rulemaking provisions of ORS Chapter 183 to establish a process for granting, retracting and restoring the time credits earned by the offender as allowed in subsections (1) to (3) of this section. [1989 c.790 60,61; 1991 c.855 § 5; 2007 c.15 § 5; 2009 c.623 § 1; 2009 c.660 17,19; 2010 c.2 1,3; 2015 c.625 § 1; 2019 c.213 § 67; 2019 c.635 § 25]