Through a pilot effort, the AMA developed standards of health care delivery for jails, prisons, and juvenile facilities, and launched an accreditation program for jail health systems. Subsequently, a program was launched to transfer the successful aspects of the pilot effort to new jails in additional States. In this project, the AMA assisted State medical societies in providing technical assistance, coordinating States' efforts, and monitoring progress. Of the original 265 jails, 22 dropped out of the program for some reason by June 1981. Virtually all of the remaining jails (98 percent) were able to improve their health care systems. Even if the dropped jails are included in the calculations, the proportion of project jails showing increases in the number of standards complied with is still over 90 percent. The average number of additional standards implemented in any given jail was just over 15 in an average period of about 16 months. About one-third of the gains were in standards designated as 'essential' and 'service,' indicating that the improvements did not just involve the writing of new policies and procedures, but included the provision of more adequate health care services as well. Appended are data on jail characteristics by State. (Author summary modified)