This document contains witness testimonies and prepared statements from the Congressional hearing called to examine issues involved in maintaining and strengthening Medicare Health Maintenance Orgranizations (HMO). Opening statements are included from Representatives Edward Roybal, Matthew Rinaldo, Mario Biaggi, Don Bonker, Robert Borski, Louise Slaughter, Harris Fawell, Ralph Regula, Jim Saxton, Jim Lightfoot, Constance Morella, and E. Clay Shaw, Jr. Congressman Dan Mica discusses problems with one HMO program and mentions legislation he is introducing to provide for study of the structure of HMOs in the future. William Roper, administrator of the Health Care Financing Administration discusses Medicare's experience with HMOs and with competitive medical plans. Other witnesses providing testimony and/or prepared statements include: (1) William Gunter, insurance commissioner, State of Florida; (2) Eva Skinner, American Association of Retired Persons, representing the Leadership Council of Aging Organizations; (3) Donald Reilly, Leadership Council of Aging Organizations; (4) Robert Crane, vice president of Kaiser Foundation Health Plan in Oakland, California; and (5) Kathryn Langwell, senior economist and project director, Medicare Competition Demonstration Evaluation, Mathematic Policy Research, Incorporated. Additional material submitted for the record is appended. (NB)