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How to recover old medical insurance claims

Old medical insurance claims are recovered in five steps: verify the claim's status with the payer, classify why it is unpaid, check the filing and appeal deadlines, take the action that matches the reason (correct and resubmit, appeal with documentation, or dispute an underpayment), and track the claim until the payer remits or issues a final determination.

A/R recovery · Published September 11, 2026 · MARR Partners

Step 1: Verify status with the payer

Do not work a claim from the aging report alone. Confirm status through the payer portal, a 276/277 claim-status transaction, or a call. Claims fall into five states: never received, pending, denied, paid (possibly underpaid or paid to the wrong party), or adjusted. Roughly a third of "old" claims in a neglected queue turn out to be not on file with the payer at all.

Step 2: Classify the reason

Reason → recovery path
ReasonRecovery path
Not on fileRefile with proof of original timely submission
Prior authorizationRetro-authorization where allowed; otherwise appeal with clinical documentation
Medical necessityFirst-level appeal with notes, policy citation, and letter of medical necessity
Coding or modifierCorrected claim (frequency code 7); appeal if the edit was wrong
Eligibility / coordination of benefitsVerify coverage for the date of service; bill the correct payer with the primary EOB
Timely filingAppeal with clearinghouse acceptance report or payer acknowledgment
UnderpaymentLine-by-line contract comparison; reconsideration, then formal dispute

Step 3: Check the deadlines before anything else

Every claim gets two dates: the timely-filing limit and the appeal limit. For Original Medicare those are one calendar year from the date of service and 120 days from the initial determination, per CMS. Commercial and Medicare Advantage limits come from the contract. Work everything within 30 days of a deadline first, regardless of balance.

Step 4: Take the matching action

  • Corrected claims go back electronically as corrections, not as new claims, so they inherit the original filing date.
  • Appeals are written to the payer's stated denial reason, cite the payer policy or the applicable Medicare coverage determination, and attach the documentation the reason calls for. A generic appeal letter loses.
  • Underpayment disputes quote the contract term and the expected allowed amount, and escalate to provider relations when the reconsideration is ignored.
  • Records requests are answered within the payer's window; an unanswered request becomes a denial.

Step 5: Track to remittance and close with a reason

Each claim is followed until the payer pays or issues a final determination. Recovered dollars are matched to the specific claim on the 835 remittance so the practice can post them. Claims that cannot be recovered are closed with a documented reason so they can be written off with confidence rather than by age.

Who should do this work

This is claim-by-claim work that competes with current billing for the same staff. Practices that keep it in-house assign a dedicated owner and measure them on recovered dollars, not days in A/R. Practices that cannot spare the staff use a contingency recovery firm, which is paid only on what it recovers. See should you outsource aged A/R?

Sources

  1. CMS, Original Medicare (fee-for-service) appeals: five levels; redetermination within 120 days, reconsideration within 180 days
  2. CMS, Medicare timely filing requirements: claims must be filed within one calendar year of the date of service
  3. CMS, Administrative Simplification: HIPAA standard transactions (837 claim, 835 remittance, 276/277 claim status, 270/271 eligibility)
  4. CMS, Medicare Claims Processing Manual (Pub. 100-04)

Figures attributed to a source are that source's; commonly used benchmarks are labeled as such. Verify deadlines against your own payer contracts.

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