Medical practices & clinics · 25 October 2026

How to Work Aged A/R and Recover Old Unpaid Claims in a Medical Practice

How small medical practices and clinics can sort, prioritize and recover old unpaid insurance claims before deadlines pass

Every practice that bills insurance builds up some old receivables. A claim gets rejected and nobody notices. A payer asks for records and the letter sits in a pile. A denial needs an appeal, but the week gets busy. Months later the aged A/R report shows a long tail of balances over 90 or 120 days, and nobody is sure which ones are still worth chasing.

Aged A/R isn't lost money yet. Much of it becomes lost money only because deadlines pass while it waits. This guide explains how to work an aged A/R report in a small medical practice: what to pull, how to sort it, what to work first, and how to stop it building up again. (If you run a therapy or behavioral health practice, our guide to recovering old unpaid therapy claims covers the same process with therapy-specific examples.)

This is general information. Filing and appeal deadlines differ by payer and contract, so always check the rules that apply to each claim.

Step 1: Pull the right report

From your practice management system, run an A/R aging report by payer, showing open insurance balances in buckets such as 0–30, 31–60, 61–90, 91–120 and over 120 days. Then pull a claim-level detail report for everything over 60 days, including:

Patient account number (keep the report inside your secure systems)
Date of service and original submission date
Payer and plan
Billed amount and expected amount
Current claim status and last activity date
Any denial or rejection codes

Make sure insurance and patient balances are separated. Patient balances need statements and patient communication. Insurance balances need payer follow-up.

Step 2: Sort before you start calling

The biggest mistake with aged A/R is working it top to bottom. Instead, sort it into groups that each need a different action:

Never received by the payer. Claims rejected by the clearinghouse or payer front end. These were never actually filed and are at the highest risk of missing timely filing.
No response. The payer received the claim but hasn't paid or denied it.
Denied. The payer issued a denial with a reason code.
Underpaid. Paid, but less than your contracted rate.
Patient responsibility misfiled as insurance. Deductibles or coinsurance sitting in the insurance bucket.
Credits and duplicates. Balances that are actually posting errors.

Groups 5 and 6 are often surprisingly large, and cleaning them up makes the real A/R much easier to see.

Step 3: Prioritize by deadline, then by dollars

Two deadlines decide whether a claim can still be paid:

Timely filing limits: how long after the date of service a claim can first be filed. Medicare's limit is generally 12 months from the date of service. Medicaid programs and commercial payers set their own limits, which are often shorter and may be set in your contract.
Appeal deadlines: how long after a denial you can appeal. For Medicare, a first-level appeal (redetermination) generally must be filed within 120 days of receiving the initial determination. Commercial and Medicaid deadlines vary.

Work claims closest to a deadline first, then the highest balances. A $40 claim that expires next week can be worth more effort today than a $400 claim with months left.

Step 4: Work each group the right way

Rejected claims

Find out why the claim was rejected (wrong member ID, subscriber mismatch, invalid code, missing NPI), fix it and resubmit as a new claim. If timely filing is close, keep proof of the original submission attempt, such as clearinghouse reports, in case you need to show you filed on time.

No response

Check claim status on the payer portal or through your clearinghouse. Common findings include "no claim on file," a request for medical records, a coordination of benefits question for the patient, or a claim pended for review. Each needs a different next step. Note the date, what you found and the reference number for any call.

Denied claims

Read the denial reason and remark codes and decide whether the claim needs:

A corrected claim (for example, a coding or modifier error). Most payers want a replacement claim marked with frequency code 7 and the original claim number, rather than a brand new claim, which may deny as a duplicate.
An appeal (for example, a medical-necessity denial), with supporting documentation and a clear letter explaining why the claim should be paid.
Information from the patient (for example, other insurance or an accident questionnaire).
A write-off, if the denial is valid and can't be overturned. Record the reason so you can prevent it next time.

Our page on denial management describes a full denial workflow that applies to medical practices as well as behavioral health.

Underpayments

Compare what was paid with your contracted fee schedule. If the payer applied the wrong rate, bundled services incorrectly or reduced a modifier-supported service, request a reprocessing or file an appeal with the contract terms.

Step 5: Track every action

For each claim, record what was done, when, the reference number, and the next follow-up date. Without notes, the same claim gets called about three times and nobody knows what the payer said. A simple shared worklist is better than memory.

Step 6: Know when to stop

Not every claim can be recovered. Claims past timely filing without proof of earlier submission, claims denied for valid reasons, and very small balances that cost more to chase than they're worth may need to be written off according to your practice's policy. Make those decisions deliberately, with a reason recorded, rather than letting balances sit forever.

Step 7: Stop the backlog from coming back

Aged A/R usually comes from the same upstream problems:

Eligibility not verified before visits
Charges entered late, so claims go out close to deadlines
Rejections not checked daily in the clearinghouse
Denials not worked within a set number of days
No one owning follow-up on claims with no response after 30 days

Set simple rules: rejections checked daily, denials worked within a week, and every claim over 30 days with no response checked on the payer portal. Review the aging report monthly, focusing on the share of A/R over 90 days.

When to get help

If your aged A/R is large, your staff are already stretched, or nobody has worked old claims in months, it can make sense to bring in outside help for the clean-up while your team keeps current billing moving. MedBill Solutions works old unpaid claims for 3% of what we recover. If nothing is recovered, there's no fee. We work inside your existing EHR or practice management system and sign a Business Associate Agreement before we access any patient information.

Next step

See how our old claims service works, or read about our ongoing billing for medical practices, which starts at 3% of what we collect. You can also send us a short enquiry with your EHR and a rough count of open claims (no patient details), and we'll reply within one business day.

Old unpaid claims? We'll work them.

You only pay 3% of what we recover. If nothing is recovered, there's no fee. We reply within one business day.

See the old claims service → Medical practice billing