Temporal patterns of drug abuse treatment reentry and other outcome measures were examined over a three-year period based on a national follow-up sample of persons admitted to treatment in the Drug Abuse Reporting Program (DARP) during 1969 to 1972. Follow-up treatment modes included methadone maintenance, residence in a therapeutic community, outpatient drug-free treatment, outpatient detoxification treatment, and a comparison group whose members completed intake only and did not return for treatment in the DARP. Treatment readmission patterns were examined in relation to outcome measures for illicit drug use, alcohol use, employment, and criminality over time. The findings showed there were reliable associations between readmission patterns and posttreatment outcomes, which suggested there were beneficial effects of drug abuse treatment.