Appealing a denial or filing a complaint

Key points:

You have the right to appeal a denied health insurance claim.
A peer-to-peer review between your healthcare provider and a physician from the insurance company may save you the trouble of filing a written appeal.
You have a limited number of opportunities to appeal a denial, so careful preparation and documentation is vital.
You have the right to file a complaint against an insurance company if you feel the company has broken a state or federal law or its own policies.

Whether appealing a denial or filing a complaint, be sure to keep written records of all interactions with your health insurance company, including dates and times, as well as the names of representatives you speak with.

How to appeal a denied claim

Dealing with insurance companies can be a complicated and frustrating process, especially when it comes to PI. Insurance companies may deny various services or treatments for PI, but you have the right to appeal that decision, generally within 180 days of receiving the denial. The explanation of benefits (EOB) for the denied claim must provide information on how to appeal the decision and the amount of time you have to do so. Some plans may provide you with a case manager for assistance regarding your grievance.

The information below applies generally to all types of private health insurance plans. However, always verify the exact process and timing with your insurance company, including whether you need to use specific appeals forms.

Filing an internal appeal

You have the right to appeal decisions in writing to your insurance company. You can find the address to submit appeals in the denial letter, your coverage documents, or by contacting your insurer using the member services telephone number on your ID card.

If the denial is for medication and your insurer requires the prescribing physician to complete a drug authorization form, verify with your provider’s office that this has been done before filing your appeal.

Before you file an appeal, you may want to request a peer-to-peer review between your healthcare provider and an insurance company doctor to discuss why you need the service, benefit, or treatment. Note that some insurers do not allow peer-to-peer reviews after a written appeal has been filed. In addition, some doctors will not participate in peer-to-peer reviews because they feel the process is another uncompensated way for insurers to deny care. However, a successful peer-to-peer review may save you from having to file an appeal.

To file an appeal, work with your healthcare provider to write a clear and simple letter with the following details:

Relevant clinical information regarding your health and treatment history, as well as medical records documenting this history. Your healthcare provider should have these.
History of any adverse reactions or side effects you have had to similar treatments. This documentation is especially important if you are appealing the denial of a specific immunoglobulin product.
Ensure that the information you provide directly addresses the reasons for the denial stated in the denial letter.

Contact your insurer after submitting your appeal to make sure they receive it.

The Affordable Care Act (ACA) requires your plan to respond to your internal appeal within certain time limits. Your plan must give you a decision about your appeal within 72 hours if the claim is for urgent care. For non-urgent services you haven’t yet received (i.e., appealing the denial of prior authorization), they have 30 days. For appeals of denials of services you’ve already received, they have 60 days.

Some plans may require more than one level of internal appeal before you can submit a request for an external review. However, all levels of the internal appeals process must be completed within the ACA-mandated timeframe.

Disputes over medical necessity

If the dispute is over the medical necessity of the service, benefit, or treatment, request that your healthcare provider write a letter of medical necessity. Your insurance company may have a template or form for this letter.

A service is medically necessary if it meets any one of the following standards:

The service or benefit will, or is reasonably expected to, prevent the onset of an illness, condition, or disability.
The service or benefit will, or is reasonably expected to, reduce or ameliorate the physical, mental, or developmental effects of an illness, condition, or disability.
The service or benefit will assist the individual to achieve or maintain maximum functional capacity in performing daily activities, taking into account both the functional capacity of the individual and those functional capacities that are appropriate for individuals of the same age.

The letter should state and provide evidence that:

The service, benefit, or treatment is medically necessary as defined above.
All other alternatives on the plan’s formulary or covered by the plan have either not been as effective/caused harm or are likely to not be as effective/cause harm based on sound clinical evidence and knowledge of the patient.

Tips for success

The following tips are from a clinical immunologist who has been successful in overturning denials for immunoglobulin replacement therapy.

Keep the appeal concise but carefully documented. Insurance companies are reviewing thousands of appeals, and you have roughly two minutes of the medical director's attention. The shorter the appeal, the shorter the turnaround time for a response.
Provide well-accepted studies and medical practice guidelines to justify the appeal.
Provide proof and documentation of serious infections/complications that have not been responsive to appropriate medical/surgical intervention, including clear imaging evidence of persistent disease, clinical documentation of infections, etc.
Focus on the rationale. A physician's letter that states "because it is medically necessary" is not specific enough to be added to an appeal letter. Precise statements are required. For example, “there were three episodes of pneumonia with a fever of 102°F, and there was a chest x-ray that showed lobar pneumonia, and five days of antibiotics were required.”
When concluding the letter, add the names of immunologists who have done scientific research on the diagnosis in question, in case the insurer requests a peer review. For example, "Should you have any questions, I would request a peer review by either Dr. John Smith or Dr. Ann Jones from the University School of Medicine."

Escalating to external review

If your plan still denies coverage after an internal review, you can ask for an independent external review [5]. During the external review, professionals with no connection to your insurance plan review your original claim. You must request an external review within 120 days of receiving your plan’s final internal review determination.

Some states have their own external review processes [6], while others use the Department of Health and Human Services’ (HHS) Federal External Review Process [7]. Your plan must include information on your denial notice about how to request an external review.

Your insurer is required by law to comply with the external reviewer’s decision regarding coverage.

Enlist your healthcare provider's help

Getting prior authorization

Healthcare providers caring for those with PI can play an integral role in ensuring their patients have access to the treatment they need.

Read tips

Templates for letter of medical necessity for Ig

Download these template letters of medical necessity to help your healthcare provider craft a succinct but detailed response that gets your Ig approved.

Download templates

Filing a complaint

If you think your insurance company has broken state or federal law, ignored their own rules or processes, or implemented a practice that is unfair to patients, you can file a complaint with either your state department of insurance [8] or the Employee Benefits Security Administration (EBSA) [9].

We have seen a rise in access issues for the PI community, including copay accumulators, denials, and policy changes that limit options. By filing a complaint, you can fight for better access to the treatment you need. To file a complaint, you must be the insured person on the policy (or the parent/legal guardian of the insured person).

How to file a complaint

If your health insurance plan is state-regulated, you can file your complaint with your state department of insurance. Visit the National Association of Insurance Commissioners (NAIC) website and select your state from the “insurance department” dropdown menu to find contact information [8]. State-regulated plans include those purchased through ACA marketplaces, individual plans, and most plans offered to state and county government employees.

If your health insurance plan is federally regulated, you can file your complaint with a regional office of EBSA [10] or through EBSA’s website [11]. Federally regulated plans include self-insured health plans offered through private employers.

Required information

Name and address of the insurance company.
Name of the insurance agent or case manager (if they are involved in the case).
Your policy and group number.
A description of the incident.
If the complaint involves a dependent under family coverage, identify the policyholder.
Date of birth of the individual and relevant demographic information.
Letter(s) of support from the healthcare provider and a lawyer (if available).
Supporting, relevant documentation that can assist in your dispute (insurance denial, copy of the policy). Always make copies, never send originals!
Details of the resolution you seek—for example, reimbursement, payment of a claim, access to your medication, or review of a particular practice.

Your insurance company is required to respond to the state department of insurance or EBSA.

References

Addressing copay accumulators and maximizers. In: Immune Deficiency Foundation [Internet]. [cited 6 Jan 2026]. Available: https://primaryimmune.org/get-involved/advocate/addressing-copay-accumulators-and-maximizers
Welcome to the Health Insurance Marketplace®. In: HealthCare.gov [Internet]. [cited 6 Jan 2026]. Available: https://www.healthcare.gov/.
Centers For Medicare Medicaid US. What’s the Medicare Prescription Payment Plan? [cited 6 Jan 2026]. Available: https://www.medicare.gov/prescription-payment-plan.
Get Medicare Help from Your Local SHIP Program. In: State Health Insurance Assistance Programs [Internet]. 14 Jan 2025 [cited 6 Jan 2026]. Available: https://www.shiphelp.org/.
How to appeal a Marketplace decision. In: Heatlhcare.gov [Internet]. [cited 6 Jan 2026]. Available: https://www.healthcare.gov/marketplace-appeals/.
Affordable Care Act: Working with States to Protect Consumers. In: Centers For Medicare and Medicaid Services [Internet]. [cited 6 Jan 2026]. Available: https://www.cms.gov/cciio/resources/files/external_appeals.
HHS-Administered Federal External Review Process. [cited 6 Jan 2026]. Available: https://maximusferp.my.site.com/FERP/s/#/home.
Insurance Departments. In: National Association of Insurance Commissioners [Internet]. [cited 6 Jan 2026]. Available: https://content.naic.org/state-insurance-departments.
Employee Benefits Security Administration. In: Department of Labor [Internet]. [cited 6 Jan 2026]. Available: https://www.dol.gov/agencies/ebsa.
Regional Offices. In: Department of Labor Employee Benefits Security Administration [Internet]. [cited 6 Jan 2026]. Available: https://www.dol.gov/agencies/ebsa/about-ebsa/about-us/regional-offices.
Ask EBSA. In: Department of Labor Employee Benefits Security Administration [Internet]. [cited 6 Jan 2026]. Available: https://www.dol.gov/agencies/ebsa/about-ebsa/ask-a-question/ask-ebsa

How to choose an insurance plan

Understanding your health benefit needs and your health insurance plan can have a huge impact on your health and your finances.

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This page contains general medical and/or legal information that cannot be applied safely to any individual case. Medical and/or legal knowledge and practice can change rapidly. Therefore, this page should not be used as a substitute for professional medical and/or legal advice. Additionally, links to other resources and websites are shared for informational purposes only and should not be considered an endorsement by the Immune Deficiency Foundation.

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