Drug Abuse Treatment Waiting Period Reduction Amendments of 1990

Drug Treatment Waiting Period Reduction Grant Program Reauthorization and Improvements Act of 1990 - Amends provisions of the Public Health Service Act relating to grants for reducing drug treatment program waiting lists to remove a prohibition of multiple grants to a single program. Directs the Secretary, in making such grants, to give priority to programs providing: (1) treatment for pregnant and postpartum women; and (2) subject to limitation, after-care services. Requires that a State agency certify the qualifications of non-State applicants for grants. Authorizes appropriations in addition to amounts otherwise appropriated and increases the aggregate limit on obligations. Directs the Administrator of the Alcohol, Drug Abuse, and Mental Health Administration to report to certain congressional committees on the waiting period reduction grant program.