According to Definitive Healthcare data, there are over 136,000 active physician group practices in the U.S., ranging in size from 1-physician solo practices to 8,700-physician practices. Group practices, like those included in the following lists, are generally divided into two categories: single-specialty and multi-specialty. Some physicians work solely as part of a physician group practice, though dual-employment between a group practice and hospital or other care facility is not uncommon.
The following tables list the largest physician groups by number of physicians and the top physician groups by Medicare charges. According to Definitive Healthcare data, the 25 largest groups by physicians employ over 92,000 physicians, with a total over $20.5 billion in Medicare charges. Meanwhile, the largest physician groups by Medicare charges employ just over 44,000 total physicians, reporting over $28.2 billion in Medicare charges.