The 1573X family of CPT codes represent muscle, myocutaneous and fasciocutaneous rotational flaps, but they don’t describe any form of free-tissue transfer with microvascular anastomosis. Muscle, myocutaneous or fasciocutaneous flaps should never be confused with adjacent tissue transfers, where skin or subcutaneous tissue alone is typically advanced to fill a defect. ASPS teaches that the 1573X “family” of codes are used for flaps in which large, vascularized muscle or fascial units (and potentially the overlying skin) are mobilized and transferred for reconstructive purposes. This includes transfer of these muscle or fascia-based flaps for the filling of oncologic defects, coverage of compromised surgical sites or functional muscle transfer.