Question: Since there are no prolonged service codes for under 30 minutes of extra E/M time, can I append modifier -21 (Prolonged evaluation and management services) to E/M visits that don't meet the 30-minute requirement for prolonged service? Answer: Not typically. Modifier -21 is only for "the highest level of evaluation and management service," according to CPT, meaning that you can only use it in conjunction with level-five services. If you append it to any other level E/M code, the claim is incorrect.
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