Aetna Medical Billing Guide

Aetna Billing Fundamentals for Medical Practices

Aetna, now a subsidiary of CVS Health, covers approximately 34 million medical members and processes hundreds of millions of claims each year. The CVS Health integration has brought changes to pharmacy benefit coordination and some billing workflows, but the core medical claims process remains consistent. Aetna offers a range of plan types including PPO, HMO, EPO, POS, and high-deductible health plans, each with its own benefit structures and billing requirements.

One area where Aetna differs from many competitors is its approach to clinical policy bulletins (CPBs). These bulletins define medical necessity criteria for specific procedures and are updated regularly. Billing teams should review the CPB for any procedure that is frequently denied for medical necessity. The bulletins are publicly available on Aetna’s provider website and provide the exact criteria Aetna’s medical directors use when reviewing claims.

Timely Filing Rules and Deadlines

Aetna’s timely filing deadline for participating providers is 90 days from the date of service on commercial plans. Non-participating providers receive 180 days. These deadlines are contractual, meaning they are specified in your provider agreement with Aetna. If your contract specifies a different deadline, the contract language takes precedence over the general policy.

For secondary claims where Aetna is the secondary payer, the filing deadline is 90 days from the date you receive the primary payer’s EOB. This is an important distinction because the clock starts from the primary payment date, not the date of service. Keep copies of primary payer EOBs with date stamps to prove timely filing on secondary claims.

Corrected claims follow the same 90-day deadline but measured from the date of the original remittance advice. Use frequency code 7 on corrected claims and always reference the original claim number. Aetna’s system will adjust the original claim rather than creating a duplicate if the corrected claim is properly linked.

Electronic Claim Submission Process

Aetna accepts electronic claims through Availity, NaviNet (now transitioning to Availity), and all major clearinghouses. The standard payer ID for Aetna commercial and Medicare Advantage claims is 60054. Some clearinghouses may use secondary payer IDs for specific Aetna products, so confirm the routing with your clearinghouse representative during setup.

Clean electronic claims are processed within 15 business days. Aetna defines a clean claim as one that has all required data elements, a valid member ID, correct provider tax ID and NPI, appropriate diagnosis and procedure codes, and no coordination of benefits questions. Claims that fail the clean claim edit are returned within 10 business days with a specific rejection reason.

Aetna has been expanding its use of artificial intelligence for claims adjudication, which means many claims are processed without human review. Claims that trigger clinical review rules are routed to medical directors, adding 15 to 30 days to the processing timeline. Common triggers include unlisted procedure codes (CPT codes ending in 99), high-cost procedures, and services billed by out-of-network providers.

Prior Authorization Requirements

Aetna requires prior authorization for a defined list of procedures that varies by plan type. The general categories include elective inpatient admissions, outpatient surgeries, advanced imaging (MRI, CT, PET), genetic testing, certain injectable medications, durable medical equipment, home health services, and skilled nursing facility admissions. Behavioral health services beyond initial evaluation often require authorization as well.

The Availity portal provides real-time prior authorization status and submission capabilities. For standard (non-urgent) requests, Aetna returns a decision within 15 calendar days. Urgent requests are processed within 72 hours, and emergency retrospective reviews within 48 hours of notification. When submitting prior auth, include the clinical rationale, relevant test results, and the treatment plan to minimize back-and-forth requests for additional information.

Aetna’s prior authorization list is updated quarterly. Subscribe to Aetna’s provider newsletter or check the provider website monthly to stay current on changes. Procedures added to the prior auth list mid-quarter typically include a 30-day grace period before enforcement begins.

Denial Prevention and Resolution

The top five Aetna denial reasons in order are: missing prior authorization (26%), coding errors (19%), eligibility or COB issues (17%), timely filing (11%), and medical necessity disputes (9%). Targeting just the top three categories through better front-end processes can reduce your overall Aetna denial rate by 40% or more.

For coding-related denials, Aetna uses Cotiviti claims editing software for prepayment review. Claims that trigger Cotiviti edits are held and may be partially or fully denied based on bundling rules, modifier requirements, or diagnosis-to-procedure mismatches. Common Cotiviti triggers include E/M services billed with minor procedures, multiple physical therapy modalities in one session, and bilateral procedure coding without modifier 50 or RT/LT modifiers.

Medical necessity denials require clinical documentation for appeal. Aetna’s clinical policy bulletins (CPBs) define the specific criteria for each procedure. When appealing, reference the applicable CPB by number and demonstrate point by point how your patient meets the listed criteria. Include operative notes, pathology results, imaging reports, and the physician’s letter of medical necessity.

Appeal Process and Timelines

Aetna allows two levels of internal appeal before external review. First-level appeals must be filed within 180 days of the denial notice. Submit through the Aetna provider portal, Availity, or by mail. Include the member ID, claim number, date of service, specific denial reason code, and all supporting documentation. Missing any of these elements delays processing.

Post-service appeal decisions are returned within 30 calendar days. Pre-service (prospective) appeal decisions come within 15 days. Urgent appeals tied to ongoing treatment receive a 72-hour turnaround. If you disagree with the first-level decision, file a second-level appeal within 60 days. A different reviewer handles the second level.

After exhausting both internal appeal levels, members can request an external review through their state’s independent review organization. Providers can initiate this process with written member authorization. External review decisions are binding on Aetna. For payment disputes (not clinical), use the provider dispute process outlined in your contract rather than the formal appeal pathway.