In 1982 California eliminated 250,000 "medically indigent adults" (MIAs) from the Medi-Cal program and transferred responsibility for their care to the counties, along with about 70% of what the state would have spent on their care had they remained in the Medi-Cal program. There is far greater variability among the counties in benefits, eligibility standards, and procedures than Medi-Cal recipients experience. A historically-based method was developed to assess the extent to which counties have met their responsibilities to MIAs and other medically indigent persons. After appropriate adjustments, the volume of health services used by this population before the transfer was compared to the volume of services provided by the county to the same population at a later point in time. This method was applied to assess the MIA transfer in Los Angeles and Orange Counties. The most striking finding from the study was the difficulty of assessing county performance of mandated responsibilities to the medically indigent. It was concluded that county health services need to improve their data systems. It is apparent even from the analysis of limited data that the transfer of MIAs from Medi-Cal to county responsibility has reduced the access of at least some low-income persons. While many MIAs received care from the two counties, as a group they did not receive the volumes of care they had received under Medi-Cal. (NB)