Authorization to be Medicaid Providers is governed by both State and Federal Medicaid Law. Provider or billing numbers are obtained through state departments of Public Assistance or Welfare. Additional information may be obtained by contacting Dr. Jan Towers, at the Academy Office of Health Policy, PO Box 40130, Washington, DC 20016, 202-966-6414, fax: 202-966-6414, email: dcoffice@aanp.org.