You may need to watch 'rendering physician' choices, too. It also includes which date of service (DOS) to report for an interpretation performed at a later date than the study: "The appropriate DOS for the professional component is the actual calendar date that the interpretation was performed." Example: This clarification could prove to be "a thorn in the paw of virtually every cardiology practice," warns Jim Collins, CCC, president of CardiologyCoder.Com in Saratoga Springs, N.Y. Cardiology offices often "conduct diagnostic testing like echocardiograms, nuclear stress tests, and EKGs on one calendar date but do not officially interpret the tests until the next day." To comply with this clarification, practices need to submit two claims "to secure compensation for all diagnostic tests that do not have same-day interpretations," he says. And list the supervising physician as rendering physician for the technical portion of the test and the interpreting physician as the rendering physician for the professional portion, Collins says. Caution: