Many purchasers and consumers of health care have become concerned about th
e quality of care being delivered in managed care plans. Little is known, h
owever, about the health plan characteristics that are associated with bett
er performance. We used survey responses from 82,583 Medicare beneficiaries
from 182 health plans to study the association of consumers' assessments o
f care with health plan characteristics. For-profit a nd nationally affilia
ted health plans received much worse scores on the outcomes of interest, pa
rticularly for overall ratings of the health plan and composite measures of
customer service and access to care. Health plans accredited by the Nation
al Committee for Quality Assurance did not receive higher scores.