POS code 31: Skilled Nursing Facility.

The CMS definition

A facility which primarily provides inpatient skilled nursing care and related services to patients who require medical, nursing, or rehabilitative services but does not provide the level of care or treatment available in a hospital.

That is the description CMS publishes for POS 31, Skilled Nursing Facility, in the Place of Service Code Set and in chapter 26 of the Medicare Claims Processing Manual. In the manual’s table it carries the Facility rate (F) designation for payment under the Physician Fee Schedule.

What it means in plain terms

POS 31 is the code for a patient who is in a SNF receiving inpatient skilled nursing care: medical, nursing or rehabilitative services that fall short of what a hospital provides. The two nursing-home codes look alike but pay differently, so the choice between 31 and 32 matters.

When it is used

• A physician or practitioner sees a patient in a SNF who is receiving inpatient skilled nursing care.
• CMS names POS 31 in its registered-inpatient rule: when the exact setting is known, a practitioner may report POS 31 for a patient in a SNF receiving inpatient skilled nursing care instead of POS 21.

Billing implications (Medicare)

The manual marks POS 31 F, so Medicare physician fee schedule services are paid at the facility rate.

POS 32 is the sibling code and carries the non-facility rate. CMS's definition of 32 describes a facility that provides skilled nursing care for rehabilitation, or health-related care "above the level of custodial care" on a regular basis. Which of the two fits a given resident depends on the care they are receiving, so check the payer or your Medicare Administrative Contractor (MAC) when the stay is unclear.

Facility-side billing for SNF stays (consolidated billing) is a separate topic handled on institutional claims. This page covers the professional-claim place of service code only.

The general rule in section 10.6 of the manual is that the POS code “generally” reflects the actual setting where the beneficiary receives the face-to-face service, with two exceptions: a registered hospital inpatient or outpatient is reported with the hospital code regardless of where the encounter happens. The code goes in item 24B of the paper Form CMS-1500 or the matching field of the 837P.

Look-alike codes

• POS 32: Nursing facility. Non-facility rate; health-related care above custodial level.
• POS 33: Custodial care facility. Room, board and personal assistance with no medical component.
• POS 21: Inpatient hospital. The minimum code for any registered hospital inpatient.

For every code in one list, with the 02 vs 10 vs 11 telehealth verdict, see the place of service code lookup.

Sources

• CMS: Place of Service Code Set — official code list and descriptions, page database updated May 2, 2024 (retrieved 2026-11-02)
• CMS: Medicare Claims Processing Manual, Chapter 26 (Rev. 12779, issued 08-09-24) — sections 10.5 and 10.6, facility and non-facility designations and special considerations (retrieved 2026-11-02)

Every definition and rule above was read from these CMS pages on November 2, 2026. Payers revise code lists, contracts and policies, so confirm anything that affects a claim with the payer. CMS itself tells billers to check each payer (Medicare, Medicaid, private plans) for how it reimburses each code.