MA prior auth after the CMS reforms: what changed for small practices

Why there's no single 'current MA prior auth rule' to learn

Medicare Advantage is administered by private insurers under contract with CMS, and each plan builds and maintains its own utilization-management program — the list of codes requiring prior authorization, the clinical criteria applied, and the process for requesting it. A biller-of-one asking what the current rules are is really asking about one specific plan, not a single national policy that covers all of them.

That's a structural fact worth sitting with before troubleshooting a specific denial: a rule that applied under one plan a patient carried last year says nothing about the plan they're enrolled in this year, even if both are marketed under the same insurer's name.

A solo practice that serves a handful of MA plans regularly still can't shortcut this by memorizing each plan's list once — the utilization-management program is exactly the part a plan revises most often, since it's the plan's own cost-control lever rather than a fixed regulatory requirement it has to keep stable year to year.

How MA prior auth differs from what Original Medicare does

Original Medicare's utilization controls run mostly through coverage determinations checked at claims processing — a much narrower gate than the pre-service authorization list an MA plan maintains. Medicare Advantage layers its own prior-authorization requirement on top of, or instead of, whatever Original Medicare would have required for the same service, which is why an MA patient's prior-auth exposure can look nothing like a traditional Medicare patient's.

Original Medicare's claims route through one of several Medicare Administrative Contractors assigned by jurisdiction 1Ref 1Centers for Medicare & Medicaid Services (2026).Medicare Administrative Contractors.That Original Medicare claims administration is regionalized across Medicare Administrative Contractors, contrasted with how Medicare Advantage plans administer their own claims directly, while an MA plan's claims go directly to the plan since the plan — not a MAC — administers the benefit itself. The comparison matters for a solo practice that sees both populations in the same week: original medicare and prior auth resolves almost the opposite way MA does, and treating the two as one Medicare population is a common source of missed authorizations.

Where the current list for a specific plan actually lives

Because each MA plan sets its own prior-authorization list, the plan's own provider portal is the only reliable source. Anthem, Aetna, UnitedHealthcare, and Cigna each publish their current Medicare Advantage utilization-management policy on their provider portals, updated on their own schedule rather than a shared CMS calendar 2Ref 2Anthem (2026).Anthem Provider Policies.Anthem's own published Medicare Advantage provider policy as a named example of where a plan's current prior-auth list lives3Ref 3Aetna (2026).Aetna Clinical Policy Bulletins.Aetna's own published Medicare Advantage provider policy as a named example of where a plan's current prior-auth list lives4Ref 4UnitedHealthcare (2026).UnitedHealthcare Policies and Protocols.UnitedHealthcare's own published Medicare Advantage provider policy as a named example of where a plan's current prior-auth list lives5Ref 5Cigna (2026).Cigna Coverage and Claims Policies.Cigna's own published Medicare Advantage provider policy as a named example of where a plan's current prior-auth list lives.

A plan's Medicare Advantage product can carry a different prior-auth list than its commercial or individual-market products sold under the same brand, so the correct lookup is the specific plan the patient is enrolled in — never the payer's name alone.

Bookmarking the specific plan's prior-authorization list, not just the payer's general provider portal, saves time on repeat lookups — a practice that sees the same three or four MA plans regularly benefits from keeping direct links to each plan's current list rather than navigating the portal from scratch each time.

Checking a code before the visit, not after the denial

The workable habit is checking prior-authorization status against the specific CPT or HCPCS code before scheduling, not inferring it from the visit type or the patient's prior year of coverage. A code that didn't require authorization last plan year can require it this year even for the same patient, since MA plans revise their utilization-management lists during open enrollment and sometimes mid-year.

Building that check into the pre-visit routine — the same routine covered in prior auth as a solo — catches the plan-year change before it becomes a denial instead of after.

What Medicare's own baseline still tells you

Even though an MA plan sets its own authorization list, the service still has to exist as a payable code somewhere, and CMS's Physician Fee Schedule is where the underlying national rate and code description live regardless of which MA plan is paying 6Ref 6Centers for Medicare & Medicaid Services (2026).Physician Fee Schedule.That the Medicare Physician Fee Schedule sets the underlying national rate and code description Medicare Advantage plans pay against, independent of plan-specific utilization management. Knowing whether a code is separately payable under Original Medicare's rules helps a biller recognize when an MA denial is a plan-specific utilization decision rather than a coding problem.

That distinction matters when appealing: a denial rooted in the plan's own medical-necessity criteria is contested differently than one rooted in the code simply not being payable at all.

When the authorization comes after the fact

Some MA plans allow a retro-auth request when a service was rendered before authorization was obtained, but retro-auth is granted at the plan's discretion and is not a substitute for checking beforehand — it's a narrow, plan-specific exception, not a routine second chance.

The mechanics of that request — what a plan needs to see, and how long it takes to hear back — are covered separately in retro-auth; treat it as a backstop for genuine emergencies, not a workflow shortcut.

The adjacent authorization path worth knowing about

A solo prescriber managing psychiatric medications for MA-enrolled patients faces prior-authorization rules that track the drug and formulary tier rather than the office-visit code discussed above — psych-med prior auths covers what's different about that specific path, and it doesn't follow the same list as procedural or E/M codes.

Medicare Advantage plans are also subject to their own payment-integrity reviews of the diagnoses submitted for risk adjustment, which puts coding accuracy on MA patients under a separate kind of scrutiny than authorization status — a distinct topic worth its own attention rather than folding it into a prior-auth checklist.