(a) Each felony sex offender sentenced by the court for a sex offense shall be required as a part of any sentence to probation, conditional release, or periodic imprisonment to undergo treatment based upon the recommendations of the evaluation made pursuant to Section 16 or based upon any subsequent recommendations by the Administrative Office of the Illinois Courts or the county probation department, whichever is appropriate. Beginning on January 1, 2014, the treatment shall be with a sex offender treatment provider or associate sex offender provider as defined in Section 10 of this Act and at the offender’s own expense based upon the offender’s ability to pay for such treatment.
     (b) Beginning on January 1, 2004, each sex offender placed on parole, aftercare release, or mandatory supervised release shall be required as a condition of parole or aftercare release to undergo treatment based upon any evaluation or subsequent reevaluation regarding such offender during the offender’s incarceration or any period of parole or aftercare release. Beginning on January 1, 2014, the treatment shall be by a sex offender treatment provider or associate sex offender provider as defined in Section 10 of this Act and at the offender’s expense based upon the offender’s ability to pay for such treatment.