Oregon Subscriber
Answer: You should first report the appropriate E/M service code for the visit based on the level of service your pulmonologist provided. Then report 99050 (Services provided in the office at times other than regularly scheduled office hours, or days when the office is normally closed [e.g., holidays, Saturday or Sunday], in addition to basic service) to indicate that the visit occurred outside of your physician's regular office hours.
Downside: Medicare payers won't reimburse for "after-hours" codes 99050-99053, but you can often persuade private payers to reimburse for the services. You may be able to convince private carriers to pay by showing how after-hours visits--on an emergency basis--can benefit patients and, at the same time, reduce the cost of claims.
Tip: Remember to consider the patient when billing for these kinds of codes. If an insurer does not cover a particular charge, and permits you to collect the fee from the patient directly, the patient may not be so understanding of the charge. Maintaining a good relationship with patients is often better than seeking extraneous payments.