Aetna Timely Filing Limit: Deadlines by Plan Type 2026

Imagine this scenario: Your front desk checks the patient’s insurance, the doctor sees the patient, notes are documented, codes are selected, and you are ready to send out a claim. Between the appointment in the examining room and getting the claim into the system, a certain clock begins ticking. Most practices never notice it until a denial letter shows up with a code they don’t recognize, CO-29, and a payment that simply isn’t coming. That clock is the timely filing limit, and for one of the largest commercial insurers in the country, understanding it isn’t optional homework. It’s the difference between getting paid and writing off revenue you already earned.
When your billing team misses a critical deadline, even the most perfectly documented medical procedure turns into uncompensated labor. Insurers are becoming increasingly stringent about their claim submission windows, and failing to track these deadlines essentially leaves hard-earned revenue on the table. For healthcare providers working with one of the nation’s largest insurance carriers, understanding the Aetna timely filing limit is absolutely non-negotiable.
This guide walks through the Aetna timely filing limit as it stands in 2026, plan by plan, so your billing team never has to guess. This presentation will address commercial insurance, Medicare Advantage, Medicaid managed care, claim correction, coordination of benefits, and recovery after missing the deadline.

Decoding the Aetna Timely Filing Limit

Before delving into specific time frames, however, it is useful to know what exactly this term means. A timely filing deadline is a deadline that limits the number of days after a certain date of service during which the service provider has to file a claim until the payer is permitted to deny it irrespective of medical necessity or eligibility of the patient.
This deadline is not a recommendation, nor is there any room for discussion once it is breached. This is a deadline set by insurers in order to keep their accounting system in order and prevent stale claims from existing endlessly. For the service providers, on the other hand, this deadline means the following: fail to meet it, and the claim is practically invalid. The service provider also cannot send a bill to the patient for the difference.

The Aetna Timely Filing Limit by Plan Type in 2026

Aetna doesn’t apply one universal deadline across every product line it administers. The window depends heavily on whether you’re in-network, out-of-network, treating a Medicare Advantage member, or billing through a Medicaid managed care contract. Here’s how the current landscape breaks down.

A few things stand out immediately. First, in-network providers get the shortest runway of the group, a reflection of the fact that contracted providers are expected to have tighter, more automated billing workflows. Second, the non-participating window changed materially in recent years; it was reduced from 27 months down to 12 months effective January 1, 2022, which is a detail some longtime billers still haven’t fully absorbed.

Commercial Plans: The 90-Day Standard

For most in-network commercial claims, the Aetna timely filing limit sits at 90 days from the date of service. That’s roughly three months, noticeably tighter than many other major commercial payers, some of which allow anywhere from 120 days to a full year. If your practice treats a patient on July 1, the claim needs to be received by Aetna no later than September 29, not simply postmarked or “in the queue” at your clearinghouse.
Out-of-network providers get considerably more breathing room: 12 months from the date of service. This gap exists because non-par providers often don’t have the same direct EDI connections or dedicated account representatives that contracted practices rely on, so the extended window compensates for the friction of billing outside the network.

Aetna Medicare Advantage: A Federal Floor, Not a Suggestion

Aetna Medicare Advantage plans operate under a different rulebook entirely. Because Medicare Advantage is a CMS-regulated program, Aetna cannot set a filing deadline shorter than the federal minimum. That floor is 12 months (365 days) from the date of service for non-contracted providers, and contracted MA providers should confirm the specific figure in their MA participation agreement, since it can vary by contract even though 365 days remains the standard benchmark.
This is one of the most common, and costly, mix-ups in medical billing. A billing team that applies the 90-day commercial rule to an Aetna Medicare Advantage claim is essentially inventing a deadline that doesn’t exist, and closing out claims that were still perfectly valid to submit. If your practice manages both commercial and MA patients, those two claim types need separate tracking logic, not a single shared calendar.

Medicaid Managed Care: Aetna Better Health plans

Aetna Better Health plans, which administer Medicaid managed care in several states, generally allow 180 days from the date of service. State-specific rules can tighten or loosen this window, though, since Medicaid programs are jointly administered by states and subject to individual state regulations layered on top of Aetna’s baseline policy.

Corrected Claims: A Longer, Conditional Window

Mistakes happen: a wrong modifier, a transposed diagnosis code, an incomplete NPI. For these situations, Aetna extends the window considerably: corrected claims can be submitted up to 365 days from the original date of service. This isn’t a blanket allowance, though. Aetna typically expects the late correction to stem from a genuine, unusual circumstance, and a practice’s overall track record of timely submissions can factor into whether the correction is honored at full value.

Coordination of Benefits (Secondary Claims)

When Aetna is the secondary payer, the clock doesn’t start at the date of service; it starts when the primary payer issues its Explanation of Benefits. For most commercial COB claims, providers have 60 days from that primary EOB date to submit to Aetna. For Medicare Advantage secondary claims specifically, the rule is a bit more generous: providers get either 12 months from the date of service or 60 days from the primary EOB, whichever date happens to be later.
To keep a secondary claim from stalling, billing teams should have four things ready before submission:

• The primary payer’s EOB or remittance advice
• The patient’s primary insurance ID
• Documentation showing exactly what the primary payer paid
• A completed coordination of benefits form

Why the Deadlines Aren’t Always the Same for Every Provider

Here’s where things get a little more layered. Aetna’s standard deadlines function as defaults, not absolutes carved in stone for every provider in every state. State insurance regulations can supersede Aetna’s standard timely filing windows in states that mandate longer periods; California, New York, and Texas are frequently cited examples where statutory rules extend beyond Aetna’s baseline policy.
There’s an important carve-out worth knowing, though: self-funded ERISA plans are generally exempt from these state insurance mandates, since ERISA plans are governed by federal law rather than individual state insurance codes. This means two patients sitting in the same waiting room, both carrying an Aetna card, could technically be subject to different filing deadlines depending on whether their employer’s plan is state-regulated or self-funded under ERISA. When in doubt, the Aetna Provider Manual and its accompanying state supplement remain the most authoritative references for confirming which rule applies.

When You Miss the Deadlines

If a claim is submitted after the deadline is crossed, Aetna denies it, which hits home as lost revenue for two reasons. First, it’s an administrative denial rather than a clinical one; the service itself was never in question, only the timing of the paperwork. Second, and more painfully, it typically cannot be balance-billed to the patient, which means the revenue is a permanent write-off rather than a delay.
Aetna doesn’t generally grant grace periods for ordinary human error, but it does recognize a narrow set of legitimate exceptions, including:

• FEMA-declared natural disasters affecting the provider’s operations
• Verified outages of the Availity portal or other submission channels
• Situations where a patient’s eligibility was updated retroactively, after the original filing window had already closed

For any of these exceptions, documentation is everything. A 277CA clearinghouse acceptance report, a timestamped Availity submission log, or certified mail receipts for paper claims can serve as proof that a claim was submitted, or attempted, within the required window.

The Reconsideration and Appeals Framework

Despite the best efforts of your front office and billing staff, claim denials will inevitably happen. Whether due to a lack of prior authorization, a transposed diagnosis code, or a bundled service dispute, you need to understand Aetna’s timeline for disputes. Aetna has separate framework phases post-denial: Reconsiderations and Appeals.
If you disagree with a claim decision, the first thing you should do is file a reconsideration. Aetna gives providers 180 calendar days from the date of the claim decision made by Aetna to ask for a formal reconsideration of the claim decision. To do this, you need to send in records or a letter explaining why the service was medically necessary and billed correctly according to the clinical guidelines used by Aetna.
If Aetna still says no to the reconsideration, the provider can then ask for an appeal of the claim decision made by Aetna. You have to do this within 60 calendar days of getting the decision from Aetna that they will not reconsider the claim decision. It is worth noting that if Aetna says no just because the claim was filed late, it is very hard to get this decision changed on appeal. So it is very important to get everything in on time to avoid this problem with Aetna.

Dispute Timeline Highlights:

• Reconsideration Request: As you receive the EOB, you must submit the reconsideration request within 180 days of it.
• Submitting Appeal: Appeals with Aetna need to be submitted within 60 days of the decision received for the reconsideration.
• Medical Necessity Appeals: These can also be filed within 180 calendar days, but this depends on the state and the specific policy, with Aetna.

Aetna Filing Practices that Optimize the Processing

With so many individual clocks ticking simultaneously; 90 days here, 365 days there, 60-day COB deadlines, 180-day appeals periods, a method of filing “timely” based solely on staff remembering is too unreliable to depend upon. Some simple practices will make a huge difference in bridging this gap:

• Segment your claims queue by plan type. Commercial, Medicare Advantage, and Medicaid managed care claims should never share a single generic deadline tracker.
• Verify eligibility and plan type before the appointment, not after, so the correct filing clock is known from day one.
• Run regular AR aging reports, bi-monthly, or weekly if you can. This helps catch claims that’re close to their deadline before they pass it.
• Proof documentation of claim submissions. This includes files that show the clearinghouse accepted them, along with the timestamps from the portal. You need this in case you have to dispute a denial because you filed on time.
• Designated personnel to watch Aetna bulletins. This is because Aetna’s rules can change quickly and without warning.

Partner with I-Med Claims for Optimal Financial Health

The rules of billing are getting stricter in 2026. This means that the healthcare providers cannot afford to leave their revenue to chance. There are a lot of deadlines to keep track of for Commercial, Medicare Advantage, and Medicaid. Healthcare providers need to stay on top of things and have the software and experts to help them. If they miss a deadline, they will not get paid for the care they give. This can hurt their practice.
At I-Med Claims, we help make medical billing easier. We take the chaos out of billing. Make it simple and predictable. Our team knows a lot about billing. We know about Aetna’s rules. We keep track of the dates. Make sure to send in claims again if they are denied. We work hard to get every dollar that our clients have earned. We do this so that healthcare providers do not have to worry about missing deadlines and not getting paid.

Conclusion

The Aetna timely filing limit is not something you can remember one time and then forget about it. It is like a group of deadlines that change based on the insurance provider, the kind of plan they have, and the state they reside in. For example, if a patient is in the network and has a claim, the deadline is ninety days. If the patient is not in the network or has Medicare Advantage, the deadline is twelve months. For Medicaid managed care, the deadline is 180 days. On top of all that, there are other deadlines for appeals and corrections.
This system is not meant to be difficult. It is a way to keep track of all the claims and make sure everything is organized. For people who provide medical care, the important thing to remember is to know what deadline is coming up for each patient. You should write down everything. Make sure you do not miss any deadlines. The deadlines are very important. You should not ignore them. If you have already earned money for taking care of a patient, you should not lose it because you missed a deadline. If you keep track of the deadlines correctly, you will not lose any money.