Medicare prior authorization list 2026: every Original Medicare program and code

Does Original Medicare require prior authorization?

Not as a rule. Fee-for-service Medicare decides whether a service is reasonable and necessary through national coverage determinations, the local coverage determinations each contractor writes, and review of the claim after the service. Prior authorization is the exception, and every exception is a named CMS program with a published code list. Two are conditions of payment nationwide: hospital outpatient department services since July 1, 2020 and the DMEPOS items on the Required Prior Authorization List. A third, probationary prior authorization, is a condition of payment for DMEPOS suppliers in their first year of enrollment from October 15, 2026. The other three let the provider choose: submit a request, or furnish the service and let the claim go to pre-payment medical review. None of them changes coverage criteria or documentation requirements; each asks for the records Medicare already requires, earlier in the process.

Medicare Advantage is outside all six. A Medicare Advantage plan sets its own prior authorization list, and the rules on this page do not apply to its members; the WISeR guide says so explicitly for Medicare Advantage and Railroad Medicare beneficiaries. For the separate CMS rule that makes Medicare Advantage and Medicaid plans exchange prior authorization requests electronically, see the 2026 payer prior authorization rule changes.

Hospital outpatient department services (nationwide)

Hospital outpatient departments must obtain a provisional affirmation from their A/B MAC before furnishing the services below. CMS created the program in the CY 2020 OPPS/ASC final rule (CMS-1717-FC) under section 1833(t)(2)(F) of the Social Security Act, which lets CMS control unnecessary increases in the volume of outpatient services, and the rule is codified at 42 CFR 419.82. Submitting the request is a condition of payment: a claim for a listed code without a provisional affirmation and its unique tracking number is denied, and so are related claims for the same service, such as anesthesia, physician and facility services, when they are furnished in the outpatient department. The MAC decides a standard request within 7 calendar days and an expedited one within 2 business days; an affirmation stays valid for 120 days, counting the decision date as day one. Hospitals that submit at least 10 requests in a year and reach a provisional affirmation rate of at least 90 percent can be exempted, and an exempt hospital stops submitting requests until CMS withdraws the exemption.

Codes CMS has taken off the OPD list: 67911 (removed January 7, 2022), 21235 (removed June 10, 2020), 63685 (temporarily removed by the CY 2021 OPPS/ASC final rule), 63688 (temporarily removed by the CY 2021 OPPS/ASC final rule), 64492 (removed August 16, 2024), 64495 (removed August 16, 2024). CMS removed 64492 and 64495 because the revised facet joint LCDs treat three- and four-level procedures as not medically necessary, so a request would always be non-affirmed.

DMEPOS Required Prior Authorization List

CMS keeps a Master List of DMEPOS items potentially subject to a face-to-face encounter, a written order before delivery and prior authorization, and selects items from it for the Required Prior Authorization List under 42 CFR 414.234. For a listed item the supplier sends the request to its DME MAC before delivery. It is a condition of payment: a claim for a listed code without a prior authorization decision and its unique tracking number is denied automatically. The DME MAC decides within 5 business days (no more than 7 calendar days), or within 2 business days when a delay could jeopardize the beneficiary's life or health. Orthoses billed with the ST modifier for an acute injury are outside the requirement but go to prepayment medical record review. Since June 1, 2026 suppliers that reach a provisional affirmation rate of 90 percent or more can be exempted for a year. The list below carries 82 codes as updated on July 29, 2026; where CMS phased an item in, every phase is shown with its states.

Changes still ahead on this list: L0456 from October 28, 2026 nationwide; L0457 from October 28, 2026 nationwide; L0486 from October 28, 2026 nationwide; L1833 from October 28, 2026 nationwide; L3761 from October 28, 2026 in California, Florida, Michigan and New York, then January 26, 2027 in Arizona, Georgia, Illinois, Massachusetts, Ohio, Oregon, Pennsylvania and Texas, then April 26, 2027 nationwide; L3916 from October 28, 2026 in California, Florida, Michigan and New York, then January 26, 2027 in Arizona, Georgia, Illinois, Massachusetts, Ohio, Oregon, Pennsylvania and Texas, then April 26, 2027 nationwide; E0194 from October 28, 2026 nationwide; K0005 from October 28, 2026 nationwide.

Added earlier in 2026: L0651 (April 13, 2026), L1844 (April 13, 2026), L1846 (April 13, 2026), L1852 (April 13, 2026), L1932 (April 13, 2026), E0651 (April 13, 2026), E0652 (April 13, 2026).

DMEPOS probationary prior authorization for new suppliers

From October 15, 2026, DMEPOS suppliers that receive Medicare enrollment approval on or after that date, including suppliers that undergo certain changes of ownership, must obtain prior authorization for the 40 codes on the probationary list (38 orthoses and 2 osteogenesis stimulators). The authority is section 1866(j)(3) of the Social Security Act and 42 CFR 424.527, which set a one-year probationary period of enhanced oversight; each supplier's year starts with its first claim. It is a condition of payment, it uses the same request process and DME MACs as the required list, an affirmed request is valid for 60 days, and it does not replace the Required Prior Authorization List: a new supplier needs prior authorization for items on both lists.

WISeR model: states, contractors and codes

The Wasteful and Inappropriate Service Reduction (WISeR) model is a CMS Innovation Center test under section 1115A of the Social Security Act. It began on January 1, 2026 and runs through December 31, 2031 in Arizona, New Jersey, Ohio, Oklahoma, Texas and Washington. Requests have been accepted since January 5, 2026 for services on or after January 15, 2026. In each state a technology company, the WISeR participant, reviews the requests alongside the A/B MAC; a provider can send the request to the participant directly or to its usual MAC, which forwards it. A provider that skips the request can still furnish the service, but the claim is routed to the participant for pre-payment medical review. Participants typically decide within 3 calendar days and within 2 days for expedited requests, an affirmation is valid for 120 days, and a non-affirmation must be reviewed by a clinician with relevant expertise before it is issued.

WISeR covers facility claims in hospital outpatient departments (type of bill 13X) and ambulatory surgical centers, and services in the office and the home. It excludes codes already under another CMS prior authorization program, which is why 63650 and the cervical fusion codes 22551 and 22552 stay with the OPD program while WISeR reviews 63655 and 22554. Since July 2026 participants exempt individual clinicians, by NPI, who submit at least 10 requests and meet the affirmation threshold. Under guide version 7.0, 13 service groups and 41 codes are in scope; Deep Brain Stimulation (NCD 160.24) and Percutaneous Image-Guided Lumbar Decompression for Spinal Stenosis (NCD 150.13) were selected, but CMS delayed implementation and will reevaluate them for a future performance year.

Ambulatory surgical center prior authorization demonstration

CMS runs a prior authorization demonstration for five service categories in ambulatory surgical centers, using the demonstration authority of section 402(a)(1)(J) of the Social Security Amendments of 1967. It covers Arizona, California, Florida, Georgia, Maryland, New York, Ohio, Pennsylvania, Tennessee and Texas, in two phases: California, Florida, Georgia, Maryland, New York, Pennsylvania and Tennessee for dates of service from January 19, 2026; and Arizona, Ohio and Texas for dates of service from February 16, 2026. Prior authorization is voluntary, but a claim submitted without a decision is stopped for prepayment medical record review. The A/B MAC decides within 7 calendar days (2 business days when expedited) and an affirmation is valid for 120 days. The ASC list follows the first five OPD categories: blepharoplasty, blepharoptosis repair and brow ptosis repair; botulinum toxin injections; panniculectomy, excision of excess skin and subcutaneous tissue (including lipectomy) and related services; rhinoplasty and related services; vein ablation and related services. It differs from the OPD list in adding J0589 and in leaving out 15847, 36474, 36476, 36479, 36483, which CMS removed from the ASC list on January 1, 2026.

Repetitive scheduled non-emergent ambulance transport (RSNAT)

The RSNAT model, authorized by section 1834(l)(16) of the Social Security Act as added by MACRA, applies prior authorization to repetitive ambulance transport: three or more round trips in 10 days, or at least one round trip a week for three weeks, for patients whose condition makes other transport unsafe. It started in New Jersey, Pennsylvania and South Carolina in 2014 and reached every state and territory, and Railroad Retirement Board beneficiaries, on August 1, 2022. Independent ambulance suppliers billing on the CMS-1500 or 837P take part; institution-based providers billing on the CMS-1450 or 837I do not. Requests are voluntary, the first three round trips may be billed without one, and after that a claim without a request goes to pre-payment review. The MAC decides within 7 calendar days, one request can cover up to 40 round trips in 60 days, and a non-affirmed request cannot be appealed but can be resubmitted as often as needed.

Codes

• A0426 Ambulance service, advanced life support, non-emergency transport, level 1 (als 1)
• A0428 Ambulance service, basic life support, non-emergency transport, (bls)

A0425 (Ground mileage, per statute mile): Mileage is billed on the same claim as the transport code and needs no prior authorization of its own; mileage paid for a transport that is later denied is subject to recoupment.

How to check whether a service needs prior authorization

1. Confirm the patient is in Original Medicare. A Medicare Advantage member follows the plan's own list, whatever this page says.
2. Find the code in the tables above. A CPT or HCPCS code that appears on no list needs no Original Medicare prior authorization, although the service still has to meet the coverage policy.
3. Match the setting and the state: the OPD list applies to hospital outpatient claims everywhere, the ASC list only to ASCs in the demonstration states, WISeR only in its six states, and phased DMEPOS codes only where their phase has started.
4. Check the date of service against the dates in the table; a request for a service before the program or phase start is dismissed.
5. Send the request with the records the coverage policy asks for to the reviewer in the table, put the unique tracking number on the claim, and deliver the service inside the validity window.

The coverage criteria themselves sit in the policies linked from each table. The guide to finding the LCD that applies in a state explains how contractors and jurisdictions are assigned, and each contractor hub, such as Novitas Solutions, lists its active LCDs with their revision dates.

Related coverage reference

Frequently asked questions

CMS guidance

The Medicare Learning Network publication that CMS issues on this topic, cited by ICN and publication date:

• Repetitive, Scheduled Non-Emergent Ambulance Transport Prior Authorization Model(MLN6805343, January 2026)Prior authorization for repetitive, scheduled non-emergent ambulance transport: who, when and how.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

• CMS DMEPOS Required Prior Authorization List (42 CFR 414.234(c)(1))
  Version Updated July 29, 2026 · effective 2026-07-29 · file dmepos_pa_required-prior-authorization-list.pdfSHA-256 1bf9bcc58284b593…
• CMS list of hospital outpatient department services that require prior authorization
  Version PDF dated August 5, 2024 · effective 2024-08-05 · file opd-services-require-prior-authorization.pdfSHA-256 775951c2413027f1…
• CMS WISeR Model Provider and Supplier Operational Guide (Appendix A, WISeR Select Items and Services)
  Version Operational guide version 7.0, July 24, 2026 · effective 2026-07-24 · file wiser-provider-supplier-guide.pdfSHA-256 5b66ca78dd36029d…
• CMS list of ambulatory surgical center services for the prior authorization demonstration
  Version PDF dated March 5, 2026 · effective 2026-03-05 · file services-list-asc-pa-demonstration.pdfSHA-256 6e637a51e16dfe6f…
• CMS DMEPOS Probationary Prior Authorization List (42 CFR 424.527)
  Version Updated September 1, 2026 · effective 2026-09-01 · file dmepos-probationary-prior-authorization-code-list.pdfSHA-256 721ef2df417c31e7…
• CMS MLN fact sheet MLN6805343: Repetitive, Scheduled Non-Emergent Ambulance Transport Prior Authorization Model
  Version MLN6805343, January 2026 · effective 2026-01-01 · file mln6805343-repetitive-scheduled-non-emergent-ambulance-transport-prior-authorization-model.pdfSHA-256 88eb091f8954b360…