Understanding Claim Response Codes: A3, 23 and PR

When a claim gets stopped before it even reaches the payer, it can feel like you never even got in line. These early rejections are frustrating because they block payment before the process even starts.

A3, 23 and PR can show up during claim follow-up, and while they represent different types of claim response codes, they’re often seen together. When they appear in combination, they generally indicate that the claim was returned because prior payment or adjustment information didn’t align with what the payer had on record.

Quick Definitions

Before we talk about fixing the problem, let’s break down what these codes mean.

A3 — Acknowledgement/Returned as unprocessable claim. The claim or encounter was rejected and never entered the adjudication system.
23 — Returned to Entity. This indicates the claim is being returned to a specific entity due to prior payment or adjustment information.
PR — Patient Responsibility. Indicates the portion the patient owes, often reflecting how a payer applied prior payments or adjustments.

Put together, these codes are the claim’s way of saying “return to sender.” They signal that the claim didn’t align with existing payment records or COB records and couldn’t be processed as-is.  

Why You Are Seeing It

These issues usually aren’t caused by large data problems, but by small inconsistencies in how prior payments or adjustments are reflected in your claim. Common causes include:

• Resubmitting a claim after an adjustment without updating payment details.

• Duplicate claims where the payer system detects an overlap with an already processed service line.

• Missing or incorrect coordination of benefits data when a secondary payer receives outdated information.

• Patient responsibility amounts that don’t match prior adjudication or payment records.

• Timing issues between claim corrections and system posting updates.  

How to Fix It Right Now

You don’t have to guess what went wrong — the claim response details will tell you exactly where to start.

• Review the rejection report or remittance information from your clearinghouse or payer portal to find the field in error.

• Compare payment and adjustment data against the payer’s most recent remittance advice.

• Correct mismatched information, including prior payment amounts and COB data.

• Validate the claim again before resubmitting.

• Resubmit promptly to avoid extended payment delays.  

How to Prevent It Next Time

A few proactive checks can help you avoid these issues altogether.

• Keep your claim history and prior payment data accurate and up to date.

• Use front-end validation tools to catch duplicates or outdated data before submission.

• Double-check COB information for accuracy between payers.

• Train billing staff to recognize how prior adjustments impact new submissions.

• Run test claims after software updates to confirm system accuracy.  

Related Codes You Might See

These codes don’t always travel alone — you might also see:

CO-16 — Claim/service lacks information or has submission/billing error(s).
A7 — Acknowledgement/rejected for invalid information.

If these appear alongside A3, 23, and PR, you may need to address multiple issues in the same claim.  

Real-World Example

A medical group resubmits claims after a payer adjustment but forgets to update prior payment details. Several claims come back with an A3 rejection, and others include 23 with a PR group code. The billing team reviews the rejection file and remittance details, finds the outdated payment information, corrects the entries, validates the claims and resubmits successfully.

Before You Resubmit — Make Sure You Do These Things

• Confirm all required fields are complete and correctly formatted.

• Verify that provider and payer IDs match current records.

• Compare the claim to prior remittance data for accuracy.

• Use your validation tool before final submission.

• Check for recent changes to payer formatting rules.  

Want to stop these errors before they happen?

Office Ally’s Service Center can flag formatting issues and mismatched data before your claims are sent, helping you get paid faster.

Want to talk to someone about how Service Center and Office Ally’s suite of solutions and products can improve your workflow? Contact our sales team today and find out how we can help.

AI Disclosure

This blog was generated with the assistance of artificial intelligence (AI) and reviewed by Office Ally’s subject matter experts for accuracy. It is intended for informational purposes only and does not constitute medical, legal, or billing advice.