Aetna prior authorization: how the approval process works

Aetna splits prior authorization by benefit type, and getting the split right is the difference between a clean approval and a request that never enters the queue. Medical precertification runs through one channel; pharmacy and specialty drugs run through another; and for several high-cost service lines Aetna delegates the clinical review to a specialty benefit manager entirely.

This guide is written for billers and authorization coordinators who process Aetna prior authorizations at volume.

What Aetna reviews

Aetna prior authorization (Aetna calls it precertification) is a pre-service clinical review that confirms medical necessity before a service is rendered or a drug is dispensed. Aetna publishes specialty-specific code lists (CPT, HCPCS, NDC) that trigger the requirement, and the list differs by plan line. Submitting a code that is not on the applicable plan’s required list wastes a submission and delays care, so confirm the code requires authorization for that specific plan before building the request.

Service categories that commonly require Aetna precertification:

• Advanced imaging (CT, MRI, PET, nuclear cardiology)
• Cardiology and interventional cardiac procedures
• Musculoskeletal surgery, spine, and interventional pain
• Radiation oncology
• Sleep studies
• Home health and post-acute care
• Specialty pharmacy and high-cost drugs

Aetna evaluates the request against its publicly posted Clinical Policy Bulletins, which define exactly what documentation establishes medical necessity for each service. A request that addresses the applicable bulletin directly moves faster than one that simply describes the procedure. Behavioral health carries its own criteria set: diagnosis, treatment history, prior treatment failure documentation, and current level-of-care justification.

Where to submit

Routing is the single most consequential decision in an Aetna workflow, because a misrouted request does not bounce back with a redirect. It sits unprocessed, and the authorization clock never starts. Confirm the destination before you build the request.

Two routing errors recur. The first is sending a specialty drug request through Availity when it belongs at CVS Caremark. The second is submitting a delegated imaging or musculoskeletal request to Aetna when EviCore by Evernorth owns the review for that plan. (CareCore National and MedSolutions are defunct EviCore brand names; do not use them on submissions.) To confirm which entity manages a given service, check Aetna’s current provider manual for that plan type or call Aetna provider services and document the reference number.

Working prior authorization across more than one payer? Start with Silna’s complete guide to prior authorization.

How to submit

Availity Essentials is Aetna’s primary electronic submission channel for medical precertification, and it supports real-time status tracking that reduces follow-up calls. Gather the same core data for every request:

• Member ID exactly as printed (a transposition error routes the request to the wrong account)
• Treating and ordering provider NPI
• CPT / HCPCS code(s) for the requested service (or NDC for drugs)
• ICD-10 diagnosis code(s) establishing medical necessity
• Complete supporting clinical documentation: progress notes, prior conservative treatment, relevant diagnostic results, and the plan of care

To request an expedited determination, call Aetna provider services and state the clinical urgency explicitly: that the standard timeline would seriously jeopardize the patient’s health or ability to regain maximum function. Expedited requests carry a shorter mandatory decision window than standard pre-service requests. The authorization clock does not start until Aetna confirms receipt of a complete request, so an incomplete submission resets the window entirely.

How to appeal a denial

Before filing any appeal, categorize the denial. Administrative denials (wrong code, missing documentation, misrouting) are reversible without spending appeal rights: correct the submission and resubmit. Filing a formal appeal for an administrative problem takes longer than a clean resubmission. Reserve the appeal process for clinical denials, where the pathway follows the plan line.

The general sequence for a clinical denial:

1. Request a peer-to-peer review. The treating physician calls Aetna’s medical management line (or EviCore’s, if EviCore issued the denial), references the denial letter, and speaks directly with the reviewing medical director within the window the denial notice specifies. This is a real-time clinical conversation, not a document submission, and it does not consume formal appeal rights.

2. File the first-level internal appeal. Submit in writing with the denial reference number, a cover letter addressing the specific denial reason, updated clinical documentation, and any supporting clinical literature. Aetna’s provider manual for the applicable plan specifies the address and deadline; both vary by plan type and state.

3. Exhaust the second internal level if the plan offers one. The denial notice states whether a second internal review exists for that plan. Complete it before requesting external review.

4. Request external review. For commercial fully-insured plans, an Independent Review Organization conducts a binding external review under state law. For Medicare Advantage, the case proceeds to the Independent Review Entity (Maximus), then to an ALJ at OMHA, the Medicare Appeals Council, and finally federal court. For Aetna Better Health (Medicaid), request a state fair hearing.

What changed for 2026

Two shifts matter for Aetna billing teams this year.

CMS-0057-F electronic prior authorization. The CMS Interoperability and Prior Authorization Final Rule requires impacted payers, including Aetna’s Medicare Advantage, Medicaid, and exchange lines, to return specific denial reasons electronically and to implement FHIR-based Prior Authorization APIs by January 1, 2027. CMS has launched an Electronic Prior Authorization initiative to drive readiness. When implemented, electronic denial reasons replace the current narrative letters for most request types on those lines, which changes how billers receive and act on denial information. Confirm FHIR API timing with your EHR vendor now.

Shrinking authorization lists. Under Congressional and CMS scrutiny of prior authorization volumes, Aetna has been removing certain lower-complexity services from its commercial required-authorization lists through 2025 and into 2026. The specific categories removed vary by market and plan type, so check Aetna’s current required-authorization list for each plan before assuming a previously required service still needs PA; submitting an unnecessary request creates work with no clinical purpose. For Aetna Medicare Advantage plans, any authorization requirement that exceeds what traditional Medicare permits for a covered service is subject to CMS audit.

How Silna reduces denials

Most avoidable Aetna denials trace to two preventable causes: incomplete clinical documentation and incorrect routing across the Availity, CVS Caremark, and EviCore split. Both are detectable before the request leaves the practice. The most common documentation failure is a diagnosis code mismatch, where the ICD-10 on the authorization form does not match the ICD-10 in the clinical note, which Aetna treats as incomplete and which resets the clock.

Silna Health’s Care Readiness Platform automates the workflow end to end: benefits verification, form population, real-time error checking, and multi-channel submission across Aetna’s medical, pharmacy, and delegated channels. Silna’s Predictive Document Intelligence flags documentation gaps and routing errors before submission, addressing the administrative failures that reset timelines and burn appeal rights. By combining automation with built-in payor communication, Silna cuts pre-visit administrative work by 95%, per Silna Health, 2026.

Silna’s strongest adoption is among ABA therapy, physical therapy, and mental health practices, plus care management for older adults, the practice types where Aetna prior authorization volume is highest and where the medical-versus-behavioral benefit split matters most. For teams managing Aetna across commercial, Medicare Advantage, and Medicaid lines, Silna coordinates the full workflow so the first submission is the complete submission. See how it applies to your payer mix at silnahealth.com.

Key terms

Precertification

Aetna’s term for prior authorization: a pre-service medical-necessity review.

Availity Essentials

Aetna’s provider portal for medical precertification submission and status tracking.

CVS Caremark

Aetna’s pharmacy benefit manager; handles drug and specialty-pharmacy prior authorization across plan lines.

EviCore by Evernorth

The specialty benefit manager Aetna delegates to for imaging, cardiology, MSK, and radiation oncology on many plans; submit and appeal through EviCore.

Clinical Policy Bulletin

Aetna’s publicly posted medical-necessity criteria by service category; the standard a submission is judged against.

Peer-to-peer review

A real-time call between the treating physician and the reviewing medical director to overturn a denial; time-limited from the denial date.

Frequently Asked Questions

This article is general educational information, not medical or insurance advice. Coverage rules and clinical criteria vary by plan and state, so consult a licensed healthcare professional or your plan administrator about your specific situation.

About the author

Jeffrey Morelli

Jeffrey Morelli is the Co-Founder and CEO of Silna Health, the first Care Readiness Platform built to remove the administrative barriers that delay care. Silna automates benefit checks, eligibility, and prior authorizations across 1,000+ payors, and is backed by $27M from Accel and Bain Capital Ventures. Before Silna, Jeff spent a decade in San Francisco building and scaling products for highly regulated industries, including leading go-to-market at Truework (Series C, acquired by Checkr).

Last reviewed: June 25, 2026.