In Wisconsin, the offender whose parole is revoked is given credit against the remaining sentence for the time spent prior to the revocation. However, a person whose probation is revoked is not given credit for the time spent between imposition and revocation of probation. An individual may be placed on probation by a court either when it withholds sentence or imposes a sentence and stays its execution. In either case, revocation of probation is effected by a two-stage administrative process within the Department of Health and Social Services. Discretionary parole is also granted by the department, and revocation is completed through the same two-stage process. In granting credit for time spent on parole but not for time spent on probation, Wisconsin is consistent with some other surrounding States, such as Minnesota, Iowa, and Michigan. In contrast, Illinois law provides credit for time served on parole and on probation. The distinction in treatment of probationers and parolees with respect to credit for time served was recently challenged in Wisconsin in State v. Aderhold (1979). The court of appeals upheld the present law, stating that the difference in treatment is rationally related to the State's legitimate governmental interests. Similar decisions were reached in Minnesota and Michigan in equal protection clause challenges regarding credit for probationers and parolees. If a decision is made to give credit for time served on probation prior to revocation, consideration must be given to allowing only partial credit rather than full credit for time served. Giving full credit for time served on probation may result in the sanction of revocation of probation not being available for a person who violates a rule of probation. No references are cited.