The feasibility of establishing a methadone maintenance treatment program network for traveling clients will be determined. All programs in the United States that currently provide methadone maintenance treatment will be identified, through contact with a variety of coordinating agencies and organizations and access to databases that provide pertinent information, and queried regarding their interest in participating in this network. The outcome of Phase I will be a comprehensive directory of publicly- and privately-funded methadone maintenance programs and a resource list of those programs indicating interest in participating in a treatment referral network, as a sending and/or receiving program. The methadone program directory developed at the conclusion of Phase I will be used during Phase II to pilot-test the acceptability, effectiveness, and efficiency for clients and staff of a treatment program network that arranges client travel throughout the country. Phase II also will provide the opportunity to determine an appropriate fee schedule for nationwide implementation of the referral service in Phase III.