Louisiana Subscriber Answer: If a pulmonologist sees a patient in the hospital after treating him in the office on the same day, you should assign only one E/M code: the hospital admit code (99221-99223, Initial hospital care, per day, for the evaluation and management of a patient ...).
When selecting the level of initial hospital care, also include the history, examination and medical decision-making involved in the same-day office visit E/M service. Be sure that the inpatient record includes any office visit documentation the pulmonologist may reference in his admission note.
CPT considers office visit and hospital care codes "per day" codes, meaning you should use only one of these codes for a given date of service. Following this guideline, most insurers will deny a same-day office visit when billed in addition to a hospital care code.
But as you indicated, if the pulmonologist did not perform a face-to-face inpatient service on the same day as the office visit, you would separately bill each E/M service.
Day 1: When the pulmonologist admitted the patient to the hospital from the office but did not see the patient in the hospital, assign the appropriate-level office visit service (99201-99215, Office or other outpatient visit ...).
Day 2: If the patient is admitted to the pulmonologist's service, and the first face-to-face inpatient-pulmonologist encounter occurs within the first 24 hours of admission, report the hospital admit code (99221-99223).