SECTION 1. Section 15(h), Article 42.12, Code of Criminal Procedure, is amended by amending Subdivision (1) and adding Subdivisions (4), (5), and (6) to read as follows:

(1) A defendant confined in a state jail felony facility does not earn good conduct time for time served in the facility but may be awarded diligent participation credit in accordance with Subdivision (6).

(4) For purposes of Subdivisions (5) and (6), "diligent participation" includes:

(A) successful completion of an educational, vocational, or substance abuse treatment program; and

(B) progress toward successful completion of an educational, vocational, or substance abuse treatment program that was interrupted by illness, injury, or another circumstance outside the control of the defendant.

(5) For a defendant who has participated in an educational, vocational, or substance abuse treatment program while confined in a state jail felony facility, not later than the 30th day before the date on which the defendant will have served 80 percent of the defendant's sentence, the Texas Department of Criminal Justice shall report to the sentencing court the number of days during which the defendant diligently participated in any educational, vocational, or substance abuse treatment program.

(6) A judge, based on the report received under Subdivision (5), may credit against any time a defendant is required to serve in a state jail felony facility additional time for each day the defendant actually served in the facility while diligently participating in an educational, vocational, or substance abuse treatment program. A time credit under this subdivision may not exceed one-fifth of the amount of time the defendant is originally required to serve in the facility. A defendant may not be awarded a credit under this subdivision for any period during which the defendant is subject to disciplinary action.

SECTION 2. The change in law made by this Act applies only to a person confined in a state jail felony facility for an offense committed on or after the effective date of this Act. A person confined in a state jail felony facility for an offense committed before the effective date of this Act is covered by the law in effect when the offense was committed, and the former law is continued in effect for that purpose. For purposes of this section, an offense was committed before the effective date of this Act if any element of the offense occurred before that date.