['Debates continue regarding optimal structures for governance and administration between medical schools and their teaching hospitals.', "Structural integration (SI) for 85 academic health centers was characterized as high (single leader or fiduciary) or low (multiple leaders or fiduciaries). Functional alignment (FA) was estimated from questionnaire responses by teaching hospitals' chief executive officers, and an index was calculated quantifying organizational collaboration across several functional areas. SI and FA were examined for their association with global performance measures in teaching, research, clinical care, finance, and efficiency.", 'AHCs with high SI had significantly higher FA, though overlap between high-SI and low-SI institutions was considerable. SI was not significantly associated with any performance measure. In contrast, FA was significantly associated with higher performance in teaching, research, and finance but not clinical care and efficiency.'] Is functional alignment , not structural integration , of medical schools and teaching hospitals associated with high performance in academic health centers?