The findings are consistent with previous comparisons of indemnity insurance and network-model and staff/group-model HMOs in elderly and nonelderly populations. The stability of results across time, geography, and populations suggests that the relative strengths and weaknesses of each system are enduring attributes of their care. Medicare enrollees seem to face the perennial cost-quality trade-off: that is, deciding whether the advantages of primary care under traditional FFS Medicare are worth the higher out-of-pocket costs.