Question: I-ve often been tempted to report modifier 21, but I-m unsure of the requirements. How should we apply this modifier? Answer: Modifier 21 (Prolonged evaluation and management services) allows you to recoup additional E/M reimbursement when the physician's services don't meet the requirements for prolonged services (99354-99355).
Maryland Subscriber
Be careful: You may append modifier 21 only to -the highest level of evaluation and management service within a given category,- CPT says. For instance, you may append modifier 21 to service code 99215 because it is the highest-level established patient outpatient code, but not to codes 99211-99214.
Example: The neurologist sees an established patient who has recently been in an automobile accident. At the time of the accident, the patient did not seek medical attention but has begun to have intermittent migraines. The physician conducts a full history and examination, meeting the requirements to report 99215. The visit lasts 65 minutes and includes 20 minutes of counseling.
In this case, the patient visit exceeds the average time for 99215 by 25 minutes with a significant amount of counseling, but there is no higher level that you could bump the E/M up to. You also cannot use a prolonged services code (99354-99355) because the time the physician spent with the patient did not exceed 30 minutes beyond the reference time for 99215. Therefore, appending modifier 21 to 99215 would be your best bet to gain extra reimbursement for the neurologist's extended service.