An extensive literature review, a survey of approximately 275 library schools, an employer survey of 2,335 of the estimated 43,600 libraries in the United States, and the development of regression models for forecasting purposes were used to identify the current and future supply of and demand for professional librarians through 1990. The study showed that in 1982 there were approximately 136,000 full time equivalent (FTE) librarians employed in libraries, with the majority having an MLS degree, and that about 80% of the approximately 7,000 graduates of library programs in 1980/81 went on to library employment, and 10% to student or unemployed status. Study projections showed that the number of library positions is expected to increase modestly in the early 1980's and then level off through 1990, while the number of individuals seeking professional library employment is expected to remain fairly constant. This document presents information on the current library labor market, projections of supply and demand, and the implications of study findings. Also provided are an executive summary, extensive tables, descriptions of survey methodology and the development of supply and demand projections, sample questionnaires, and a 330-item bibliography. (ESR)