Although it is recognized that services must be developed for IV drug users (IVDUs) with AIDS, little is known about the costs and financing of their use of inpatient and community-based services. Whereas it is assumed that most IVDUs with AIDS are eligible for Medicaid and other public programs, it is unclear what proportion actually enroll. And, while significant levels of uncompensated services are reported by hospitals serving IVDUs wit AIDS, their fiscal impact has yet to be measured. Since it is expected that the treatment needs of IVDUs with AIDS will have an even greater impact on delivery and financing of AIDS- related services in the future, several policy questions must be addressed, including: Who are IVDUs with AIDS? What resources do they use and what factors impact on their use? What does it cost to care for them? And, what is the fiscal impact of this group on public payers and hospitals? The proposed research uses a state AIDS information system developed in Maryland, to: 1) identify socio-demographic and clinical characteristics of IVDUs with AIDS; 2) measure their use of inpatient and community-based services during the course of their illness and identify factors related to use and direct costs; 3) evaluate the fiscal impact of IVDUs with AIDS borne by Medicaid and other public programs; and 4) measure the level of uncompensated inpatient costs incurred by IVDUs with AIDS. The results of this research are expected to be useful to states in developing similar AIDS information systems, to policy makers in planning and financing programs required to meet future needs of IVDUs with AIDs, and for researcher concerned with socio- demographic, clinical, and service profiles of IVDUs.