Radiation Therapy Prior Authorization 2026: MA Clock, WISeR

Three things changed radiation therapy prior authorization 2026 workflows at once. Medicare Advantage and Medicaid plans came under federal decision deadlines and must now state a specific reason for every denial. Traditional Medicare began testing prior authorization in six states through the WISeR model, which does not yet include radiation therapy. And every payer’s radiation authorization list had to be rewritten for the new delivery codes 77402, 77407 and 77412 and the professional-only 77387-26. That last change caused most of the denials.

These changes give practices three things to check payers against: a decision deadline, a stated reason for each denial and a code map.

Medicare Advantage decision deadlines: CMS-0057-F

The CMS Interoperability and Prior Authorization final rule (CMS-0057-F) was finalized in January 2024 with a compliance date of January 1, 2026 for its operational provisions. It applies to Medicare Advantage organizations, state Medicaid and CHIP fee-for-service programs, Medicaid and CHIP managed care plans, and Qualified Health Plan issuers on the federal exchanges. Employer-sponsored and other commercial plans are outside it.

Requirement	Who	When
Expedited (urgent) decision within 72 hours	MA, Medicaid, CHIP (QHP issuers exempt from the timeframes)	Starting January 1, 2026
Standard decision within 7 calendar days	Same	Starting January 1, 2026
Specific reason for every denial, whatever channel the request came through	All impacted payers	Beginning 2026
Prior authorization metrics posted publicly on the payer’s website, annually	All impacted payers	First set by March 31, 2026
Prior Authorization, Provider Access, Payer-to-Payer and Patient Access APIs	All impacted payers	By January 1, 2027

For a radiation course, 7 calendar days is the number to write on the authorization tracker. A Medicare Advantage request for a 77407 course submitted on a Monday is due back by the following Monday; if it is not, you have a federal rule to cite in your escalation, and a denial without a stated reason is itself out of compliance. The metrics postings, due by the end of March each year starting 2026, show which plans deny the most.

WISeR: traditional Medicare prior authorization, in six states, not for radiation

The Wasteful and Inappropriate Service Reduction (WISeR) model runs six performance years, January 1, 2026 through December 31, 2031, in Arizona, New Jersey, Ohio, Oklahoma, Texas and Washington. Technology vendors paid a share of the spending they help avert run prior authorization, or prepayment medical review if no request is submitted, for a selected list of traditional Medicare services. Requests opened January 5, 2026 for dates of service on or after January 15, 2026.

Novitas lists 14 service categories: electrical nerve stimulators, sacral nerve stimulation for urinary incontinence, phrenic nerve stimulators, vagus nerve stimulation, induced lesions of nerve tracts, epidural steroid injections (excluding facet joint injections), percutaneous vertebral augmentation, cervical fusion, arthroscopic lavage and debridement for the osteoarthritic knee, hypoglossal nerve stimulation, incontinence control devices, diagnosis and treatment of impotence, percutaneous image-guided lumbar decompression, and skin and tissue substitutes. Radiation therapy and oncology services are not on it. Inpatient-only and emergency services are excluded, services may be added quarterly, and CMS says a gold card exemption for compliant providers may come later.

Two cautions. The quarterly add list can grow, since categories are chosen for safety concerns, published coverage criteria and prior fraud reports. And the CY 2027 OPPS proposed rule separately proposes hospital outpatient prior authorization for eight more botulinum toxin codes, again not radiation therapy.

The commercial pledges

In June 2025 more than 50 health plans, including UnitedHealthcare, Aetna, Cigna, Humana, Elevance, Kaiser Permanente and Centene, signed commitments with CMS. By January 1, 2026 a patient’s new plan is to honor existing prior authorizations for similar in-network services for 90 days after a plan change, and plans are to explain determinations and the appeal path in plain terms for fully insured commercial coverage. For 2027, the plans committed to a standardized electronic prior authorization process and to answering at least 80 percent of electronic approvals in real time. These are voluntary commitments, not regulations.

The code remap: the main source of 2026 denials

Every radiation authorization list had to be rewritten on January 1, 2026, and old-code approvals had to carry over.

Payer document	What it did
UnitedHealthcare, December 23, 2025 notice (Medicare Advantage, Community Plan, commercial, Exchange)	Retired prior authorization for 77385, 77386, G6015, G6016 (IMRT), 77014, G6001, G6002, G6017 (IGRT) and 77401, G6003 to G6014 (2D/3D). Requires it for 77402, 77407, 77412 and 77387-26 for oncologic and hematologic diagnoses, for treatment starting on or after January 1, 2026. Approvals issued under old codes for courses starting before 2026 need no new request; UHC said it would map them to the new codes.
UnitedHealthcare commercial medical policy 2026T0613L, effective March 1, 2026	Added a criterion allowing up to 10 fractions for accelerated partial-breast irradiation with 3D technique (the whole-breast limits of 21 fractions, or 33 with listed criteria, remain). Added coding notes: 77412 only for the Level 3 criteria, with documentation that explains why; IGRT technical work included in 77402, 77407 and 77412, professional as 77387-26.
eviCore for Cigna, Radiation Oncology Coding Manual V1.0.2026, effective January 1, 2026	One unit of 77402, 77407 or 77412 per date of service (two for BID with modifier 76 or 77 on a separate line); one 77387-26 per date, modifier 26 required; no simulation codes 77280, 77285 or 77290 during an IMRT course; 77336 one unit per 5 fractions; adaptive planning has no CPT code and no additional planning units may be billed for it. LUGPA called the accompanying clinical guideline the most restrictive it had seen, citing IMRT to 3D downgrades and limits on IGRT, SBRT, hypofractionation and re-irradiation.
BlueCross BlueShield of Tennessee, January 1, 2026 list	Added 77436 to 77439 (superficial therapy) to its authorization set; deleted 77014, 77385, 77386, 77401 and G6001 to G6017.

A Palmetto GBA loading error denied 77387-26 for early 2026 dates until a mass adjustment reported resolved March 6, 2026, and UnitedHealthcare listed 77387 and 77439 as bundled until January 18, 2026. Neither was a prior authorization problem, but both could look like one on the remittance.

Worked example: two courses in early 2026

Course A is a 20-fraction prostate IMRT course approved in December 2025 under 77386 with IGRT, starting January 12, 2026, UnitedHealthcare Medicare Advantage. Under UHC’s notice no new authorization is needed; UHC maps the approval to the new codes. The claim lines, though, must be 20 units of 77407 and 20 units of 77387-26. If a line denies for “no authorization,” the fix is a call to confirm the mapped approval, not a new request.

Course B is a left breast course with deep inspiration breath hold starting in February, same plan. The request has to name 77412 (active motion management is a Level 3 criterion) and 77387-26, and the note must say why Level 3. The plan must give a standard decision within 7 calendar days and a specific reason if it denies or approves 77407 instead.

What to do now

Put the 7-day and 72-hour deadlines on your authorization tracker for every Medicare Advantage, Medicaid and CHIP request, with the submission timestamp, and escalate on day 8.
Ask for the stated reason on every 2026 denial from an impacted payer before you write an appeal; a denial without a reason is a compliance issue to raise with the plan.
Request 77412 with the criterion named (motion management, multiple isocenters, mixed fields, total skin) and attach the documentation up front, since UHC and eviCore both review for it.
Re-check carried-over approvals. Any course approved in late 2025 under 77385, 77386 or a G-code should show the 2026 codes on the payer’s portal before the first claim.
Download each MA plan’s March 2026 metrics posting and keep it with your payer file.
Flag authorizations at charge entry. Payer-specific rules in Iridium Suite’s claim scrubber can carry authorization requirements per payer, so a 77412 line for a UnitedHealthcare plan with no authorization on file is flagged before the claim is sent; see the claim scrubber.
Watch WISeR’s quarterly list if you treat in Arizona, New Jersey, Ohio, Oklahoma, Texas or Washington.

Radiation therapy prior authorization in 2026: the Medicare Advantage clock, WISeR and payer code remaps