Many DUI drunk driving offenders are placed under the supervision of a probation officer, although for some minor or first-time offenses, the offender is simply placed on probation for a length of time without being required to contact the probation officer. Some offenders may only need to contact their probation officers once a month by telephone or in person, while others may have weekly meetings with a probation officer and may be subjected to random tests for the presence of alcohol or illegal drugs. In other cases, the court can order that the offender's car be equipped with a special ignition-locking device that works in conjunction with a breath test and prevents the car from starting if the driver's blood-alcohol level is too high. In Washington, a first time offender that is convicted of DUI will be ordered to have an ignition interlock in their car for one year. In addition, especially if a person has multiple convictions, programs of intensive supervision have been developed  that require offenders to wear an electronic monitoring device or call the probation office with their location and travel plans several times each day. Many plans require offenders to obtain various kinds of treatment for their personal problems, such as attending Alcoholics Anonymous meetings, seeking drug-abuse counseling, attending anger-management classes, or taking part in group therapy.

Probation officers act in a dual capacity in the criminal justice system. On the one hand they are supposed to help the offender get his or her life in order and stay out of jail. On the other, they are expected to monitor compliance with the criminal sentence and be an arm of the law and promptly report any violations. For this reason, they are not bound by any requirements of confidentiality and, in fact, are expected to inform on the clients to the court. Once a probation officer determines that a client has violated the terms of probation, a probation review or revocation proceeding is commenced.

Often, probation is structured so that the offender receives a suspended jail or prison term along with the probation. If probation is revoked, the offender will be incarcerated under the suspended-sentence provisions. Court decisions require that a person who is facing revocation or his or her probation be given a written statement of the alleged violation; an opportunity to attend the hearing and present his or her side of the story, submit documentary evidence, and call and cross-examine witnesses; the right to have the revocation decision made by an impartial decision maker; and the right to a written decision reciting the evidence relied on and the reasons for revoking the probation. Violations only need to be proved by a preponderance of the evidence, not beyond a reasonable doubt. Most offenders are represented a lawyer at this stage of the proceedings.