The diverse substance abuse rehabilitation services which are available to drug addicted individuals in Knox can vary in several different ways. Some alcohol and drug abuse rehab programs are conducted in a residential or inpatient facility, where clients reside for the duration of their rehabilitation which provides a more therapeutic treatment setting. Others offer drug and alcohol abuse rehab programs on an outpatient basis which allows for more flexibility, although outpatient centers are not always a suitable substance abuse rehab service for people in Knox who are struggling with long term drug addiction issues. Whether or not inpatient or outpatient drug and alcohol abuse rehabilitation services are chosen, there are also different lengths of time that men and women will be required to continue to be in the drug and alcohol rehabilitation program. For instance, many short-term programs offer programs for 4 weeks or less, while long-term centers will call for at least a 90 day stay.