We tested the association between medical home characteristics and measures of technical quality and patient experience of care in the 21 clinics of a large medical group that had all achieved level III recognition from the National Committee for Quality Assurance. There was substantial variation among them in both scores on the recognition instrument and in clinic performance measures. However, the few statistically significant associations that were identified disappeared when correction for multiple analyses was applied. We conclude that among primary care clinics recognized as high-level medical homes, the instrument used to assess medical home characteristics cannot differentiate their quality.