Appeals Center
Complete Appeal Process A–Z

Before filing an appeal, investigate the denial thoroughly. Read the ERA/EOB to identify the CARC (Claim Adjustment Reason Code) and RARC (Remittance Advice Remark Code) that explain the denial reason.

Determine whether the denial is a coding/billing error, a medical necessity denial, an authorization denial, a coverage exclusion, or a timely filing denial. The denial type determines your response strategy.

Review the original claim for errors — wrong CPT/HCPCS code, missing modifier, incorrect ICD-10 diagnosis, wrong place of service, or missing NDC. If the claim has a correctable error, a corrected claim may be more appropriate than an appeal.

Check the payer's policy for the denied service. Review the payer's coverage criteria, clinical policy bulletin, or medical necessity guidelines to understand what the payer requires to cover the service.

If the denial is for medical necessity, review the clinical documentation. Does it support the service? Does it address the payer's coverage criteria? If the documentation is insufficient, strengthen it before appealing.

Document your investigation findings — these will form the basis of your appeal letter. Include the denial reason, the payer policy reviewed, the clinical documentation available, and the argument for overturning the denial.

A corrected claim resubmits a claim that was denied due to a billing or coding error — wrong code, missing modifier, incorrect patient information, or missing NDC. The claim is corrected and resubmitted through the standard claim submission process.

An appeal is a formal challenge to a payment decision on a claim that was processed correctly based on the information submitted — typically a medical necessity denial, authorization denial, or coverage dispute. Appeals require a formal letter and supporting documentation.

Use a corrected claim when the denial is due to: CO-16 (missing/invalid information), CO-18 (duplicate/service), coding errors, or missing modifiers. Use an appeal when the denial is due to: CO-50 (not medically necessary), CO-197 (authorization), CO-96 (non-covered service), or CO-29 (timely filing — appeal only if you have proof of timely submission).

Corrected claims are typically processed faster than appeals (15–30 days vs 30–90 days). If the denial is correctable, always file a corrected claim first. If the corrected claim is denied, then file an appeal.

Some payers require a corrected claim (with frequency code 7) rather than an appeal for billing errors. Check the payer's provider manual for their specific requirements.

Never submit a corrected claim as a new claim — always reference the original claim number and use the appropriate frequency code to indicate a corrected submission.

The strength of your appeal depends on the quality of your supporting documentation. Include clinical notes, physician orders, prior authorization records, diagnostic test results, and treatment plans.

For medical necessity appeals, include the clinical notes from the date of service and relevant prior visits that demonstrate the patient's condition and the need for the service.

Include the physician order or referral that documents the medical justification for the service. The order should specifically state why the service was necessary.

Include relevant diagnostic test results — lab reports, imaging reports, pathology reports — that support the diagnosis and the need for the service.

Include the payer's own coverage criteria or clinical policy bulletin for the service. Show how the patient meets the payer's stated requirements — this is the strongest argument.

Include peer-reviewed clinical literature if the service deviates from standard protocols or if the payer denied the service as experimental/investigational.

Organize documentation logically: appeal letter first, then clinical notes, then physician orders, then test results, then payer policy. Number each page and include a table of contents for large packets.

Medical necessity is the most common reason for appeal. The payer denied the service because they determined it was not medically necessary based on the information submitted.

To appeal a medical necessity denial, demonstrate that the service was reasonable and necessary for the diagnosis or treatment of the patient's condition. Reference the payer's own clinical criteria.

Review the payer's clinical policy bulletin or medical necessity guidelines for the service. These documents specify the criteria the payer uses to determine coverage. Show point-by-point how the patient meets each criterion.

Include the treating physician's letter of medical necessity, which explains the clinical rationale for the service. The letter should address the specific denial reason and cite the relevant clinical evidence.

For surgical procedures, include operative notes and any pre-operative documentation that supports the need for the procedure. For imaging services, include the ordering physician's rationale and any prior conservative treatment.

For inpatient stays, include the admission note, daily progress notes, and discharge summary. Show why inpatient care was necessary rather than outpatient or observation.

If the payer denied the service as experimental or investigational, include peer-reviewed clinical literature, FDA approval status, and professional society guidelines that support the service.

Every payer publishes coverage policies, clinical policy bulletins, and medical necessity guidelines. These documents specify the criteria the payer uses to determine whether a service is covered.

Review the payer's policy for the denied service before appealing. The policy will tell you exactly what documentation and criteria the payer requires to cover the service.

For commercial payers, check the payer's website for clinical policy bulletins, medical policies, or coverage determination guidelines. For Medicare, check CMS National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs).

Cite the payer's own policy in your appeal letter. Show how the patient meets the criteria specified in the policy. This is the strongest argument because you are using the payer's own standards.

If the payer's policy is more restrictive than Medicare or industry standards, note this in your appeal. Some payer policies are more restrictive than CMS guidelines, and this can be grounds for appeal.

Check for policy updates. Payer policies change frequently, and a service denied under an old policy may be covered under a current policy. Verify the policy in effect on the date of service.

Timely filing is the deadline for submitting a claim or appeal to the payer. Each payer sets its own timely filing deadline — typically 90–365 days from the date of service for claims and 30–180 days for appeals.

If a claim is denied for timely filing (CO-29), verify the date of service, the original submission date, and the payer's timely filing deadline. If you have proof of timely submission (clearinghouse report, electronic submission confirmation), appeal with the proof.

If the original claim was submitted timely but the payer denies it as untimely, appeal with the electronic submission confirmation, clearinghouse report, or CMS 1500 claim tracking number. The payer's timely filing denial may be an error.

For appeals, the timely filing deadline is separate from the claim timely filing deadline. Appeal deadlines are typically 30–180 days from the denial date — check the payer's provider manual for the specific deadline.

Missing the timely filing deadline for claims usually forfeits the claim. Missing the appeal deadline usually forfeits the appeal right. Track all deadlines systematically and file before the deadline.

Some payers allow retroactive timely filing for good cause (e.g., natural disaster, system outage). Check the payer's policy for exceptions and document the reason for late filing.

Appeal deadlines vary by payer, plan type, and appeal level. Always verify the deadline with the payer's provider manual and the specific plan contract.

Medicare Part A/B Redetermination (Level 1): 120 days from the Remittance Advice date. Reconsideration (Level 2 — QIC): 180 days from the redetermination decision.

Medicare Advantage First-Level Appeal: 60 days from the denial date. Second-Level Appeal: 60 days from the first-level decision. External Appeal: after internal appeals are exhausted.

Commercial (ACA) Internal Appeal: 180 days from the denial date. External Appeal: 4 months after the internal appeal denial (state laws may vary).

Medicaid State Fair Hearing: varies by state, typically 30–90 days from the denial date. Check the state Medicaid agency's appeal rules.

Missing the appeal deadline usually forfeits the appeal right. File appeals before the deadline and keep proof of submission (certified mail receipt, electronic submission confirmation, or fax confirmation).

Level 1 — First-Level Appeal: Filed directly with the payer. Uses the payer's standard appeal form or letter. Reviewed by the payer's appeals department. Most denials are overturned at this level with proper documentation.

Level 2 — Second-Level Appeal: Filed after a first-level appeal is denied. Reviewed by a different clinical reviewer or appeals committee. May require additional documentation or a peer-to-peer review request.

Level 3 — External Appeal: Reviewed by an Independent Review Organization (IRO) outside the payer. Required under ACA for commercial plans. IRO decisions are binding on the insurer. Used for medical necessity and experimental/investigational denials.

Level 4 — State Fair Hearing or Court: For Medicaid, a state fair hearing after the plan-level appeal. For Medicare, an Administrative Law Judge (ALJ) hearing after the QIC decision. For commercial plans, litigation after the external appeal.

Medicare has 5 levels: (1) Redetermination, (2) Reconsideration by QIC, (3) Administrative Law Judge, (4) Medicare Appeals Council, (5) Federal District Court. Each level has its own deadline and process.

Escalate to the next level only after the current level is denied. Each level requires a new submission with the denial from the previous level attached. Do not skip levels — the payer will return or deny the appeal.

Track every appeal from submission to resolution. Record the appeal submission date, the appeal confirmation number, the expected decision date, and the actual decision date.

Use a tracking spreadsheet or practice management system to monitor appeal status. Include fields for: patient name, claim number, denial date, appeal level, submission date, confirmation number, deadline, expected decision date, actual decision date, outcome, and notes.

Follow up on appeals that exceed the payer's stated decision timeline. Most payers must respond within 30–60 days for first-level appeals. If no response is received, call the payer's provider relations department.

Document every interaction with the payer — call reference numbers, representative names, dates, and conversation summaries. This documentation is essential if you need to escalate.

Track appeal outcomes and analyze trends. If a particular payer or denial type has a high overturn rate, focus your appeal efforts there. If a particular denial type has a low overturn rate, focus on prevention.

Track the financial impact of appeals — dollars appealed, dollars overturned, and the cost of the appeal process (staff time, postage, supplies). This helps justify the appeal program's ROI.

Common appeal statuses include: Submitted (appeal has been submitted to the payer), In Review (payer is reviewing the appeal), Additional Information Requested (payer needs more documentation), Decision Pending (payer is finalizing the decision), Approved (appeal overturned — claim will be paid), Denied (appeal upheld — claim remains denied), and Partially Approved (some services approved, others denied).

When the payer requests additional information, respond promptly — typically within 10–30 days. Missing this deadline may result in an automatic denial.

When the appeal is approved, verify that the claim is reprocessed and paid. Check the next ERA/EOB for the adjusted payment. If the payment is not received within 30 days, follow up with the payer.

When the appeal is denied, review the denial reason. Determine whether to escalate to the next appeal level, file a corrected claim, or write off the claim. Consider the dollar amount, the likelihood of success, and the cost of further appeals.

When the appeal is partially approved, verify which services were approved and which were denied. Appeal the denied services separately if appropriate.

Document the final outcome of each appeal — approved, denied, partially approved, or withdrawn. Use this data to analyze appeal effectiveness and identify process improvements.

Use a structured template for appeal letters to ensure consistency and completeness. Include: payer name and address, patient name and ID, claim number, date of service, denial reason (CARC/RARC), appeal argument, supporting documentation list, and requested action.

Start the letter with a clear statement of appeal: "I am writing to appeal the denial of claim [number] for [patient name] for services rendered on [date of service]. The claim was denied for [denial reason]."

Address each denial reason specifically. If the denial cites multiple reasons, address each one. Do not leave any denial reason unaddressed — the payer may uphold the denial on that basis.

Cite the payer's own policy or clinical criteria. "According to [payer name] Clinical Policy Bulletin [number], this service is covered when [criteria]. The patient meets these criteria because [explanation]."

Include a clear request for action: "I request that you overturn the denial and reprocess the claim for payment. If you require additional information, please contact me at [phone/email]."

Sign the letter and include your title, contact information, and NPI. Attach all supporting documentation and include a list of attachments at the end of the letter.

Maintain a professional, factual tone in all appeal communications. Avoid emotional language, accusations, or threats. State the facts clearly and let the evidence speak.

Be concise and specific. Avoid lengthy narratives — the appeal reviewer needs to understand the argument quickly. Use bullet points and numbered lists for clarity.

Address the reviewer respectfully: "Dear Appeals Reviewer" or "Dear [Payer Name] Appeals Department." Do not use informal salutations.

When calling the payer, have the claim number, patient name, and appeal reference number ready. Be prepared to take detailed notes including the representative's name, call reference number, and a summary of the conversation.

Document all communications in writing. If a payer representative makes a verbal commitment (e.g., "we will reprocess the claim"), follow up with a written confirmation referencing the call.

If the appeal is time-sensitive (e.g., patient health is at risk), state this clearly and request expedited review. Most payers have an expedited appeal process for urgent cases.

Pre-Appeal Checklist: (1) Read the ERA/EOB and identify the CARC/RARC, (2) Verify the denial reason, (3) Review the original claim for errors, (4) Check the payer's policy for the service, (5) Determine if a corrected claim or appeal is appropriate, (6) Gather supporting documentation.

Appeal Letter Checklist: (1) Payer name and address, (2) Patient name and ID, (3) Claim number, (4) Date of service, (5) Denial reason (CARC/RARC), (6) Appeal argument addressing each denial reason, (7) Payer policy citation, (8) Requested action, (9) Signature and contact information, (10) List of attachments.

Documentation Checklist: (1) Clinical notes from the date of service, (2) Physician order or referral, (3) Relevant diagnostic test results, (4) Treatment plan, (5) Payer coverage criteria, (6) Peer-reviewed literature (if applicable), (7) Prior authorization records (if applicable), (8) Operative notes (for surgical procedures).

Submission Checklist: (1) Appeal letter signed and dated, (2) All supporting documentation attached, (3) Submission method confirmed (mail, fax, portal, email), (4) Appeal deadline verified, (5) Proof of submission obtained, (6) Tracking system updated with submission date and confirmation number.

Follow-Up Checklist: (1) Check the payer's stated decision timeline, (2) Follow up if no decision received by the expected date, (3) Document the outcome, (4) Verify payment if approved, (5) Determine next steps if denied (escalate, correct, or write off), (6) Update the tracking system with the final outcome.