Why Claims Get Denied Even After Prior Authorization – And How to Prevent It

Many healthcare providers assume that once a prior authorization (PA) is obtained, a claim is guaranteed to be paid. The truth is, prior authorization is conditional approval, not a guarantee of payment. Even with a valid PA, claims can still be denied for a variety of reasons.

Common Reasons Claims Are Denied Post-Authorization

• CPT/HCPCS mismatch: The code billed doesn’t match what was approved.
  

• Diagnosis mismatch: The diagnosis submitted on the claim differs from the one tied to the authorization.
  

• Dates of Service: The service was provided outside the approved period.
  

• Units/Visits Exceeded: The number of visits or units billed exceeds what the authorization allowed.
  

• Provider/NPI mismatch: The rendering provider’s NPI doesn’t match the one on the authorization.
  

• Patient coverage issues: Coverage lapsed or changed after authorization was obtained.
  

• Provider credentialing issues: Credentialing expired or lapsed, or provider is out-of-network.
  

• Payer-specific rules: Some payers have unique rules such as referrals, bundling edits, or administrative approvals that affect payment.

How to Prevent and Resolve Denials

1. Pre-Submission Checks

   Confirm the authorization number, CPT, diagnosis, DOS, units, and provider NPI before submitting the claim.

   
   

2. Verify Eligibility & Coverage

   Ensure the patient’s plan is active on the date of service.
   

3. Track Provider Credentialing

   Maintain up-to-date records of credentialing and re-credentialing deadlines to avoid lapsed status.
   

4. Document Denials & Payer Rules

   Create a living payer cheat sheet that tracks denial codes, recurring payer-specific quirks, and solutions. This becomes an internal reference to prevent repeat errors.
   

5. Correct & Resubmit or Appeal

   Fix claim errors, resubmit if appropriate, or file an appeal with supporting documentation.
   

6. Use the Cheat Sheet Proactively

   Reference it before submitting claims to avoid repeating known issues and speed up resolution.

Turning Denials Into Learning Opportunities

Each denial is an opportunity to improve workflows and reduce future errors. By combining a pre-submission checklist with a living payer cheat sheet, your team can stay proactive, streamline claim submission, and minimize lost revenue.

Optional Resource:

We’ve created a payer denial tracker template to help billing teams implement these steps efficiently.