Prior Authorization

Medicare Denied Claim: No Prior Authorization

Name: Medicare Denied Claim: No Prior Authorization
Creator: Barley Billing Team
Published: 2026-03-26

Written by Barley Billing Team, Medicare Billing Experts | Last reviewed March 26, 2026

Does your notice say something like this?

"The authorization number is missing, invalid, or does not apply to the billed services"

"Prior authorization was not obtained"

"Precertification/authorization/notification absent"

"This service requires prior approval that was not obtained"

If so, you're in the right place. Here's what it means and what to do.

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.

However, the outcome depends on your situation. Retroactive authorization is sometimes possible, especially for urgent or emergency services. Your appeal is stronger if the service was medically necessary and your provider can support that with documentation.

Keep in mind that only about 11.5% of denied prior authorization requests are appealed, meaning many people give up without trying.

What To Do Next

Contact your provider’s office immediately. Ask them if they can request retroactive authorization from your plan. Some plans allow this, especially for urgent situations, and it can resolve the denial without a formal appeal.
Check whether the authorization was actually obtained. It’s possible your provider got the authorization but forgot to include the number on the claim. Ask the billing office to verify and resubmit if needed.
If retroactive authorization isn’t possible, file an appeal. Follow the instructions on your denial notice. Ask your provider to include a letter explaining why the service was medically necessary.
Keep records of everything. Save your denial notice, any correspondence with your provider or plan, and notes from phone calls (including dates, names, and what was discussed).
For Medicare Advantage plans, know that standard appeals must be decided within 30 days. You can request an expedited appeal (decided within 72 hours) if waiting could seriously harm your health.

Sources

Want us to review your denial for free? Send us your notice and we'll tell you if it's worth appealing →

Appeal Deadlines — Check Your Notice for Exact Dates

Original Medicare

120 days from the date on your MSN

Medicare Advantage

At least 60 days (check your denial notice for exact deadline)

Not sure which you have? Check the top of your denial notice. If it names a private insurance company (like Humana, UnitedHealthcare, or Aetna), you have Medicare Advantage. If it says "Centers for Medicare & Medicaid Services," you have Original Medicare.

Frequently Asked Questions

What is prior authorization?

Prior authorization (also called precertification or pre-approval) means your health plan must approve a service before it's provided. If the approval isn't obtained ahead of time, the plan may refuse to pay even if the service was medically necessary.

Is prior authorization my responsibility or my doctor's?

In most cases, it's your provider's responsibility to request prior authorization. However, it's a good idea to ask your provider whether prior authorization is needed before any scheduled procedure. Your plan may also send you information about which services need approval.

Can my provider get retroactive authorization?

Sometimes. Some Medicare Advantage plans allow providers to request authorization after the service has been provided, especially in urgent situations. Ask your provider to contact the plan and request retroactive authorization. There is no guarantee it will be granted, but it's worth trying.

Does Original Medicare require prior authorization?

Traditional Medicare has historically required very little prior authorization. However, starting in 2026, CMS is piloting a prior authorization program for 17 specific procedures in six states (Arizona, New Jersey, Ohio, Oklahoma, Texas, and Washington). Medicare Advantage plans, on the other hand, commonly require prior authorization for many services.

Want Us to Check Your Denial?

Send us your denial notice and we'll review it for free. We'll tell you if it's worth appealing and exactly how to do it.

This information is for educational purposes only and is not legal or medical advice. Always verify with your doctor's office and insurance company.