POS 20: urgent care facility.

What CMS says POS 20 means

Location, distinct from a hospital emergency room, an office, or a clinic, whose purpose is to diagnose and treat illness or injury for unscheduled, ambulatory patients seeking immediate medical attention.

Code name: Urgent Care Facility. CMS lists it as effective January 1, 2003. Source: CMS Place of Service Codes for Professional Claims, retrieved 2026-11-02.

How POS 20 differs from the settings around it

• POS 11, office: a location, other than a hospital, SNF, military treatment facility, community health center, State or local public health clinic or ICF, where the health professional routinely provides examinations, diagnosis and treatment on an ambulatory basis. An urgent care definition turns on unscheduled patients seeking immediate attention.
• POS 17, walk-in retail health clinic: a walk-in clinic within a retail operation providing preventive and primary care, described by CMS as "other than an office, urgent care facility, pharmacy or independent clinic". Effective May 1, 2010.
• POS 49, independent clinic: a location not part of a hospital and not described by another code, providing services to outpatients only. Effective October 1, 2023.
• POS 23, emergency room, hospital: a portion of a hospital where emergency care is provided.

Why the label on the door is not enough

The CMS wording turns on the facility's purpose and patient flow. A center that markets itself as urgent care but operates by appointment as a routine office may fit POS 11 better. A hospital-run walk-in clinic raises a separate question: if it is a provider-based department of a hospital, POS 19 or 22 may apply. Provider-based status is governed by 42 CFR 413.65, which defines a hospital's "campus" as the area immediately adjacent to its main buildings, other areas within 250 yards of them, and areas the CMS regional office determines to be part of the campus.

What to check before you submit

• Read the CMS definition against how the site actually operates: unscheduled patients seeking immediate attention, not a hospital ER, an office or a clinic.
• Confirm whether the site is owned and billed as a hospital department. If so, look at POS 19 and 22 and the payer's rules.
• CMS tells billers to check each payer for its reimbursement policy for each code. Some payers pay differently by setting, so a wrong code can change both the denial risk and the payment.
• If a claim went out with the wrong POS, correct and resubmit as the payer directs. Medicare allows a party to ask for reopening within 1 year for any reason (42 CFR 405.980(c)).

Worked example (hypothetical)

A walk-in center accepts patients without appointments for sprains and infections and is not part of any hospital. It bills POS 20. Another site run by the same group sees established patients by appointment for routine exams: POS 11 is the closer CMS definition there. Both locations bill under one tax ID, but the place of service follows the setting where each visit happened.

Sources

• CMS: Place of Service Codes for Professional Claims — code names and descriptions (retrieved 2026-11-02)
• eCFR: 42 CFR 413.65 (provider-based status) — regulation text as of the eCFR issue dated 2026-10-29, retrieved 2026-11-02
• eCFR: 42 CFR 405.980 — regulation text as of the eCFR issue dated 2026-10-29, retrieved 2026-11-02

Every code description and rule above was retrieved from these pages on November 2, 2026. X12 code text is copyrighted by X12 and quoted only for the codes explained here; the complete lists are at x12.org. Payers revise code lists, contracts and policies, so confirm anything that affects a claim or a deadline with the payer.