Swing Beds can be either inpatient or nursing facility. You need to verify with the facility which status the patient was on the date the service was provided.
Per the Medicare Claims Processing Manual (Pub 100-04, Chapter 12, Section 30.6.9 D)
D. Visits to Patients in Swing Beds
If the inpatient care is being billed by the hospital as inpatient hospital care, the hospital
care codes apply. If the inpatient care is being billed by the hospital as nursing facility
care, then the nursing facility codes apply.
That is, if the patient is assigned inpatient hospital status, bill with codes 99221--99239. For subsequent hospital visits, use codes 99231-99233.
If the patient is assigned nursing facility status, bill with nursing facility E/M codes, 99305--99310.
30.6.10 - Consultation Services
(Rev. 2282, Issued: 08-26-11, Effective: 01-01-11, Implementation: 11-28-11)
Consultation Services versus Other Evaluation and Management (E/M) Visits
Effective January 1, 2010, the consultation codes are no longer recognized for Medicare Part B payment. Physicians shall code patient evaluation and management visits with E/M codes that represent where the visit occurs and that identify the complexity of the visit performed.
In the inpatient hospital setting and the nursing facility setting, physicians (and qualified nonphysician practitioners where permitted) may bill the most appropriate initial hospital care code (99221-99223), subsequent hospital care code (99231 and 99232), initial nursing facility care code (99304-99306), or subsequent nursing facility care code (99307-99310) that reflects the services the physician or practitioner furnished. Subsequent hospital care codes could potentially meet the component work and medical necessity requirements to be reported for an E/M service that could be described by CPT consultation code 99251 or 99252.
There is additional information in the Medcare Claims Processing Manual (Chapter 12) but these are the highlights that address your situation.