Prior Authorization on Medicare Denial Guide — Barley

Medicare Denied Claim: No Prior Authorization

Thu, 26 Mar 2026 00:00:00 +0000

What This Means

Your claim was denied because the service required prior authorization (advance approval) from your health plan, and that approval wasn’t obtained before the service was provided. This is one of the most common reasons for Medicare Advantage claim denials.

This denial doesn’t mean the service wasn’t needed. It means the required administrative step of getting the plan’s approval in advance was missed.

Why This Happens

Your provider didn’t request prior authorization. Some services require advance approval from your plan. If your provider didn’t submit the request before providing the service, the claim can be denied.
The authorization request was incomplete or never processed. Your provider may have started the authorization process but didn’t complete it, or the request was lost in the system.
The authorization number wasn’t included on the claim. The provider obtained authorization but didn’t put the authorization number on the claim form when billing.
The service was provided on an emergency basis. Emergency services generally don’t require prior authorization, but follow-up care or non-emergency services provided during the same visit might.
You’re in a Medicare Advantage plan. MA plans require prior authorization far more often than Original Medicare. In 2024, Medicare Advantage insurers made nearly 53 million prior authorization determinations, according to KFF.

Should You Appeal?

Appeal outlook: Mixed

Prior authorization denials have a surprisingly strong overturn rate when appealed. KFF (2024) found that approximately 81% of appealed Medicare Advantage prior authorization denials were fully or partially overturned. Additionally, a 2022 OIG report found that 13% of MA prior authorization denials would have been approved under Original Medicare’s coverage rules.

Medicare Denied Claim: Prior Authorization Expired

Thu, 26 Mar 2026 00:00:00 +0000

What This Means

Your claim was denied because the prior authorization on file either expired before the service was provided or didn’t match the service that was actually performed. Even though your plan originally approved something, the approval wasn’t valid for what was ultimately billed.

This is a common issue when there are scheduling delays or when the service delivered differs from what was originally authorized.

Why This Happens

The authorization expired before your appointment. Prior authorizations have an expiration date. If your appointment was delayed beyond that date, the authorization is no longer valid. Common validity periods range from 30 to 90 days.
The service performed was different from what was authorized. If the surgeon authorized a procedure on your left knee but operated on your right knee, or if a different procedure was performed than what was approved, the authorization won’t match.
The claim used different billing codes than the authorization. Even if the service was the same, a mismatch between the CPT or HCPCS codes on the authorization and the claim can cause a denial.
More units or sessions were provided than authorized. If your authorization covered 6 physical therapy visits but you had 8, the extra visits may be denied.
The service was provided by a different provider. Some authorizations are specific to a particular provider. If you saw a different doctor or went to a different facility, the authorization may not apply.
Administrative delays in scheduling. Long wait times for specialist appointments or surgical scheduling can push the service date past the authorization expiration.

Should You Appeal?

Appeal outlook: Weak

Expired or mismatched authorizations are difficult to appeal successfully because the plan’s approval had specific terms that weren’t met. However, there are situations where an appeal may be worth pursuing:

Medicare Denied Claim: Referral Missing or Invalid

Thu, 26 Mar 2026 00:00:00 +0000

What This Means

Your claim was denied because your health plan required a referral from your primary care provider (PCP) for this service, and the referral was either missing, expired, or didn’t match the service you received. Without a valid referral on file, the plan won’t pay for the visit.

This is primarily a Medicare Advantage issue. Original Medicare does not require referrals to see specialists.

Why This Happens

Your PCP didn’t submit a referral. Your primary care provider may not have known you were seeing a specialist, or the referral process was overlooked.
The referral expired. Referrals are typically valid for a set time period (often 60 to 90 days, depending on your plan). If your appointment was after the referral expired, the claim can be denied.
The referral was for a different service. A referral to see a cardiologist doesn’t automatically cover a cardiac procedure. The referral needs to match the specific service that was billed.
The referral wasn’t linked to the claim. Your PCP may have issued a referral, but it wasn’t properly connected to the claim in the billing system.
You saw a specialist without going through your PCP first. In HMO-style Medicare Advantage plans, you typically need to start with your primary care provider, who then refers you to the specialist.
Emergency exception not applied. Emergency visits generally don’t require referrals. If you were seen in an emergency but the claim was coded as a routine visit, the referral requirement may have been incorrectly applied.

Should You Appeal?

Appeal outlook: Mixed

Many referral denials are resolved without a formal appeal. Your provider can often obtain a retroactive referral or correct the referral information and resubmit the claim.

Medicare Denied Prior Authorization Request

Thu, 26 Mar 2026 00:00:00 +0000

What This Means

Your health plan reviewed your provider’s request for prior authorization and decided not to approve the service. This means the plan won’t cover the cost of this service at this time.

This is different from a claim denial. A prior authorization denial happens before you receive the service. The good news is that you have the opportunity to appeal before any bills are involved.

Why This Happens

The plan didn’t find the service medically necessary. Based on the information submitted, the plan determined the service doesn’t meet their criteria for medical necessity for your condition.
The documentation was incomplete. Your provider may not have included enough clinical information to support the request. This is one of the most common and fixable causes.
The plan requires a different treatment first. Some plans use “step therapy,” which means they require you to try a less expensive treatment before approving the requested one.
The service isn’t covered under your plan. The service may be excluded from your specific plan’s benefits, separate from the prior authorization question.
Coding or administrative errors. The wrong diagnosis code, procedure code, or other administrative details on the request can trigger a denial.

Should You Appeal?

Appeal outlook: Mixed

Prior authorization denials are worth appealing, especially when your doctor believes the service is necessary. A 2022 OIG investigation found that 13% of Medicare Advantage prior authorization denials would have been approved under Original Medicare’s standard coverage rules. That means some services are being denied by MA plans even though Medicare would normally cover them.