1 month is considered "short-term rehabilitation," and anything longer is considered "long-lasting rehab." The only distinction in between rehab lengths is that treatment is more intensive in short-term rehab given that more treatment is being condensed into a much shorter period of time. Unlike inpatient rehab, when you decide for an outpatient program, each action of the rehabilitation process is usually completed at a different center.As soon as that's completed, the actual therapy can begin 90 days is usually a minimum, but lots of people continue seeing a therapist or participating in group therapy for multiple years. The longer you invest in rehab, the more expensive it will be. However, those who have extreme addictions may not get all the help that they need in short-term rehabilitation.