Question: I-m new to billing for a physician who visits patients in nursing facilities. What are the criteria I should use to determine whether to bill with place of service code 31, 32 or 33? Florida Subscriber Answer: Even seasoned billers can get confused with place of service (POS) codes 31 (Skilled nursing facility), 32 (Nursing facility) and 33 (Custodial care facility), because a facility can have both skilled nursing and non-skilled nursing beds at the same time. Here's when you-ll use each of these POS codes. 31: You should use skilled nursing facility (SNF) code 31 when your physician treats a patient who is in a skilled bed at the time of service. This means the patient has a medical condition that requires skilled nursing care, such as injections or ventilation. Medicare must authorize skilled nursing services and considers them a Medicare Part A expense. A patient is allowed only a certain number of SNF days per year. You need to find out from the facility whether the patient is considered an SNF patient or if he has used up his SNF days and is considered a nursing facility patient. Remember: If a nursing facility brings a patient to the physician's office, you should report POS code 11 (Office) on the claim form. 32: You should bill using nursing facility POS code 32 if the patient is not on Part A Medicare, or has used up his SNF days and instead is on long-term care and receiving medical, nursing or rehabilitative services. The best way to determine what type of bed the patient is in is to communicate with the administrative or billing office in the nursing facility. 33: You should use POS code 33 for a custodial care facility. These facilities provide patients with personal assistance services on a long-term basis, but do not provide medical care. Patients are mobile in a custodial care facility, so be sure there is medical necessity for your physician to see a patient at the facility and not in your office. These facilities are often referred to as assisted-living facilities. -- The answers to the Reader Questions were provided and/or reviewed by Barbara J. Cobuzzi, MBA, CPC-OTO, CPC-H, CPC-P, CPC-I, CHCC, president of CRN Health-care Solutions, a coding and reimbursement consulting firm in Tinton Falls, N.J.