How to appeal a denied insurance claim

How to appeal a denied claim, in short

To appeal a denied insurance claim, find the exact denial reason on the remittance, decide whether the claim needs a correction or a dispute, gather the documentation that answers that reason, and submit a reconsideration or appeal through the payer’s required channel before its deadline. Then track the appeal until the payer responds, and escalate to the next level if the denial is upheld and you still believe it’s wrong.

The step most often skipped is the first one. An appeal that doesn’t address the specific reason code is likely to be upheld, no matter how strong the clinical case is.

First, make sure it needs an appeal

Not every denial should be appealed. Some are faster to fix another way:

• Billing errors you made, such as a wrong modifier, a missing diagnosis link or a typo in the member ID, usually call for a corrected claim rather than an appeal.
• Claims that were rejected, not denied, were never processed and are resubmitted rather than appealed. Our article on claim rejection vs denial explains the difference.
• Requests for information, such as records or a patient update on other coverage, need the missing item sent.
• Payer decisions you disagree with, such as medical necessity, bundling, authorization or coverage denials you believe are wrong, are what appeals are for.

Our guide to common claim denial codes helps sort which bucket each denial belongs in.

Reconsideration vs formal appeal

Many commercial payers offer two stages. A reconsideration (sometimes called a reopening, claim review or first-level dispute) is an informal request to look at the claim again, often submitted through the payer’s portal, sometimes by phone for simple errors. A formal appeal is a written request with documentation, reviewed under the payer’s appeal process, and sometimes required after a reconsideration is denied.

The names, steps and deadlines differ from payer to payer, and your network contract may define them. Check the provider manual and the denial notice for each payer rather than using one process for all of them.

What to put in an appeal letter

A clear appeal letter is short and specific. It should include:

1. Identifying details. Patient name, date of birth, member ID, claim number, date of service, billed amount, and the rendering provider’s name and NPI.
2. What you’re appealing. The denial date and the exact reason and remark codes from the remittance.
3. Why the denial is wrong. A direct answer to the denial reason, in a few sentences. For a medical necessity denial, summarize the clinical facts that support the service. For a bundling denial, explain why the service was separate and distinct. For an authorization denial, give the authorization number or the reason one wasn’t required.
4. The policy basis. Reference the payer’s own medical or payment policy, the plan’s coverage terms, or your contract, where it supports your position.
5. What you’re asking for. Reprocessing and payment of the claim, or of the specific lines denied.
6. A list of enclosures. So the reviewer can see everything you’ve sent.

Keep it factual and polite. Reviewers handle large volumes, and a letter that gets to the point quickly is easier to approve.

Common appeal mistakes

• Sending the same claim again with no new information or explanation.
• Arguing a different point from the one the payer denied, such as defending the coding when the denial was for authorization.
• Attaching the whole chart instead of the notes for the date of service, which slows the review.
• Using the wrong channel or form. Many payers require their own appeal form or portal submission, and an appeal sent elsewhere may not be logged.
• Appealing a claim that only needed correcting, which uses up time and sometimes an appeal level.

What documentation to attach

Attach what answers the denial reason, and not much more:

• The relevant clinical notes for the date of service, such as the visit note, procedure note or test results
• The order or referral, where required
• The prior authorization record, if one was obtained
• The remittance or EOB showing the denial
• The payer policy section you’re citing
• Proof of timely filing, if the denial was for late filing, such as clearinghouse acceptance reports
• A letter of medical necessity from the provider, when the clinical case needs explaining beyond the notes

Send only the minimum protected health information needed for the appeal, and use the payer’s secure submission channel.

Appeal deadlines

Every payer sets its own appeal deadlines, and they range widely. Some commercial plans allow a short window from the denial date, others allow longer, and network contracts sometimes set different terms from the general provider manual. Medicaid plans have their own rules by state. Check the denial notice and your payer contract for each claim, and calendar the deadline the day the denial is posted.

A missed appeal deadline usually ends the matter, however strong your case was.

Medicare’s five levels of appeal

Medicare fee-for-service claims follow a set five-level process:

1. Redetermination by the Medicare Administrative Contractor (MAC) that processed the claim. The request must generally be filed within 120 days of receiving the initial determination.
2. Reconsideration by a Qualified Independent Contractor (QIC). The request must generally be filed within 180 days of receiving the redetermination decision.
3. Hearing before an Administrative Law Judge (ALJ).
4. Review by the Medicare Appeals Council.
5. Judicial review in federal district court.

The ALJ hearing and federal court levels require a minimum amount in controversy, and those thresholds are adjusted every year. The later levels also have their own, shorter filing windows. Check the current CMS guidance before escalating. Medicare Advantage plans run their own appeal processes under separate rules, so don’t apply fee-for-service steps to them.

Tracking appeals so they don’t slip

Appeals fail quietly when nobody follows up. A simple tracking routine prevents most of that:

• Log every appeal with the claim number, payer, amount, denial reason, date sent, submission method and deadline for the next level.
• Save proof of submission, such as the portal confirmation, fax confirmation or mail tracking number.
• Set a follow-up date based on the payer’s stated response time, and check status when it passes.
• Decide on escalation promptly when an appeal is upheld, while the next level’s window is still open.
• Report outcomes by denial reason. If one reason keeps winning on appeal, the fix probably belongs upstream. If one keeps losing, stop spending time on it and fix the cause instead. Our guide on how to reduce claim denials covers that side.

How RCM24 handles appeals

Our claims and denial management team writes appeals that answer the specific denial reason, attaches the documentation that supports it, tracks every deadline and escalates when it’s worth it. Denials older than 90 days are worked through our A/R recovery service.

If you have denied claims you haven’t had time to appeal, request a free A/R audit. We’ll show you which ones are still within their appeal windows and which are worth the effort, from your own claims data.