POS 31 — Skilled Nursing Facility (Part A Stay): Place of Service Code Explained

POS 31: What It Identifies

POS 31 identifies physician services to patients in a skilled nursing facility during a Medicare Part A covered stay. The Part A detail matters: SNF consolidated billing swallows many services into the facility's payment during covered stays, and POS 31 is the flag payers use to apply those edits.

Use POS 31 For

Physician/NP visits to SNF patients within a Part A covered stay
Regulatory visits (admission assessments, required rotations) in skilled stays
Services separately payable OUTSIDE consolidated billing (physician professional services generally are)

Don't Use It For

Long-term custodial residents past their Part A benefit — POS 32
Assisted living facilities — different POS entirely
Assuming everything is billable: ancillaries during Part A stays often belong to the SNF under consolidated billing

How POS 31 Affects Payment

Physician professional services at POS 31 remain separately payable, but many ancillary services (therapies, most supplies, some diagnostics) fall under SNF consolidated billing — the SNF gets paid, and outside providers must bill the SNF, not Medicare. Practices serving SNFs without understanding consolidated billing write off revenue they should be invoicing the facility for.

Common POS 31 Billing Errors

Billing Medicare directly for consolidated-billing services (denials, then confusion) instead of invoicing the SNF
POS 31/32 confusion when patients exhaust Part A mid-month — status changes, POS follows
E/M code family errors: nursing facility codes (99304–99316), not office codes

Consolidated Billing: What You Can and Cannot Bill Separately

This is the part that makes POS 31 genuinely different from every other place of service, and it is where most of the money is lost. During a covered Part A skilled nursing stay, Medicare pays the facility a bundled per-diem that is intended to cover almost everything the resident receives. That bundle is called SNF consolidated billing, and it means a large share of services you might normally bill directly are the facility's responsibility, not Medicare's.

The critical exclusion works in your favour: physician professional services are carved out of consolidated billing. Your evaluation and management work, your procedures, your professional interpretations — those you bill directly to Part B with POS 31. What gets swept into the facility's per-diem is most of the ancillary and technical side.

Service	Who bills it during a Part A stay
Physician professional services (E/M, procedures)	You, direct to Part B with POS 31
Professional interpretation of a diagnostic test	You — the 26 component
Physical, occupational and speech therapy	The SNF
Most routine drugs, supplies and equipment	The SNF
Technical component of most lab and imaging	The SNF
Specific high-cost excluded services	You — see the CMS exclusion list

The workflow that prevents the denial: before billing anything for a nursing-home resident, confirm whether the patient was in a covered Part A stay on that date of service. If they were, check whether your service sits on the current consolidated billing exclusion list. If it is not excluded and not a physician professional service, the claim belongs to the facility — submitting it to Medicare produces a denial, and chasing that denial is wasted work because the claim was never yours to bill.

Certain high-cost categories are specifically excluded from the bundle and remain separately billable — historically these have included things like cardiac catheterisation, CT and MRI, radiation therapy, certain chemotherapy and its administration, and some prosthetics. The list is specific and it changes, so treat it as something to look up rather than memorise.

Consolidated billing exclusion lists and covered-procedure lists are updated by CMS annually — verify the current year's list before relying on any specific service category.

The mirror-image setting is POS 32, where the resident is custodial or the Part A benefit is exhausted — consolidated billing does not apply and normal Part B billing resumes. Because a single resident can move between the two mid-stay, the safest habit is to verify status per date of service rather than per patient.

Related POS Codes

POS 32 — Nursing facility POS 12 — Home POS 21 — Inpatient

← Back to the full POS code reference

Reviewed by Hassan Raza Awan, Founder — 4+ years of hands-on U.S. medical billing experience. General billing information — verify against current CMS guidance and your payer contracts.

Frequently Asked Questions

What is SNF consolidated billing in plain terms?

During a Part A stay, Medicare pays the SNF one bundled rate covering most services the resident needs — so outside providers of those bundled services bill the SNF for payment, not Medicare. Physician professional services are the big exception and stay separately billable. Know which side of the line each service sits on before rendering it.

How do we know if the patient is POS 31 or 32?

Ask the facility for the stay status: in a covered Part A stay = 31; custodial/long-term (Part A exhausted or never applicable) = 32. Status flips mid-stay when benefits exhaust, and your claims need to flip with it — a monthly census reconciliation with each facility keeps this clean.

What is SNF consolidated billing?

During a covered Part A skilled nursing stay, Medicare pays the facility a bundled per-diem intended to cover most services the resident receives. That bundle is consolidated billing. Physician professional services are carved out and remain separately billable by the physician with POS 31, but most therapy, routine supplies and the technical component of lab and imaging become the facility's responsibility.

Can I bill Medicare directly for a patient in a Part A SNF stay?

For your professional services, yes - those are excluded from consolidated billing and you bill Part B directly using POS 31. For most ancillary and technical services the claim belongs to the facility, and submitting it to Medicare produces a denial. Certain specifically excluded high-cost services also remain separately billable, so check the current CMS exclusion list.

POS 31: Skilled Nursing Facility (Part A Stay)