A health insurance denial for your infant’s care — a NICU stay, a specialist referral, a medication, a diagnostic test — arrives as a single letter or a line on an Explanation of Benefits. The letter does not tell you that you have a federal right to challenge it. It does not explain that an external, independent reviewer can override the insurer’s decision. And it does not mention that the deadline to file is in that same letter, buried in fine print.
This guide covers the full federal appeals process for health insurance denials affecting infants and young children: your rights under both the Affordable Care Act and ERISA, the step-by-step process, the exact deadlines, and how to escalate when internal appeals fail.
This is educational information, not legal advice. For complex denials involving significant sums, consulting a patient advocate or health insurance attorney may be warranted.
The two federal frameworks that govern your appeal rights
Two federal laws establish the floor for health insurance appeals in the United States. Which one applies to your plan determines what rules govern.
The Affordable Care Act (ACA) — If your health insurance is a fully-insured plan (meaning the insurer bears the financial risk) purchased through an employer, a state marketplace, or directly from an insurer, the ACA’s claims and appeals regulations apply. These are codified at 45 CFR § 147.136. ACA-governed plans must also comply with any additional protections in your state’s external review laws.
ERISA (Employee Retirement Income Security Act of 1974) — If your health insurance comes through a large employer that self-funds its health benefits (meaning the employer itself pays claims rather than an insurance company), ERISA governs your appeal rights. Approximately 60% of workers in large-employer plans are in self-funded arrangements. Self-funded ERISA plans are exempt from state insurance laws, including many consumer-friendly state external review protections.
The practical difference: ACA-governed plans are subject to binding external review under state or federal law. Self-funded ERISA plans are subject to federal external review, which generally follows similar standards but is governed by federal regulation rather than state law.
How to find out which framework applies to your plan: Call the member services number on your insurance card and ask: “Is this plan fully insured or self-funded?” Your plan’s Summary Plan Description — which you can request from your HR department or the plan administrator — will also state this.
Step 1: Request the denial in writing and understand the reason code
Before you write a word of an appeal, you need to know exactly why the claim was denied.
Every denial must include a specific reason. Common denial categories:
- Medical necessity — the insurer determined the service wasn’t medically necessary
- Not covered / exclusion — the service is excluded from your plan
- Prior authorization required — the service needed pre-approval that wasn’t obtained
- Out-of-network — the provider wasn’t in your plan’s network
- Duplicate claim or billing error — administrative rather than clinical
Request a copy of the full denial notice in writing, including the specific reason code and the clinical criteria the insurer used to make the decision. Under the ACA, you have the right to receive the exact criteria, guidelines, or clinical policy used in the denial determination. Request it. This is what you’ll use to construct your appeal.
Also request a copy of your child’s relevant medical records from the treating provider, if you don’t already have them. Your pediatrician, NICU team, or specialist’s office can provide a clinical letter supporting the medical necessity of the denied service.
Step 2: File the internal appeal
The internal appeal is the first mandatory step. You must complete it before you can request external review in most cases.
Deadline to file: Under federal ACA rules, you have at least 180 days from the date you receive the denial notice to file an internal appeal. Some states set shorter windows, and some plans may specify a longer window — always check your Summary Plan Description. The 180-day federal minimum is the floor; you cannot be required to file sooner.
What to include in your internal appeal:
- A clear written statement identifying the denied claim (date of service, provider name, type of service, claim number from your EOB).
- Your argument for why the denial was wrong, specifically addressing the reason given. If denied for medical necessity, explain why the service was medically necessary based on your child’s specific condition.
- A supporting letter from the treating physician or specialist. This is the most powerful element of a medical necessity appeal. Ask the provider to write specifically to the criteria the insurer used — not just a general note, but a letter that addresses the insurer’s stated rationale.
- Relevant medical records supporting the claim: clinical notes, lab results, imaging reports, NICU records, or specialist evaluations.
- Citations to clinical guidelines, if applicable. If your pediatrician’s care followed AAP guidelines or other established clinical standards, reference those explicitly.
Send everything in writing. If submitting by mail, use certified mail with return receipt. If submitting online through the insurer’s portal, save confirmation screenshots.
Timeline for the insurer’s decision: For standard internal appeals, the insurer must decide within 60 days (for ACA plans). For urgent care appeals, the timeline is 72 hours.
Step 3: Request external review
If the insurer upholds the denial after your internal appeal, you can request external review. This step sends your case to an Independent Review Organization (IRO) — an accredited third-party organization that reviews the denial independently of the insurer.
This is where your strongest leverage lies. Under both ACA and federal ERISA external review rules, if the IRO overturns the denial, that decision is binding on the insurer. The insurer must authorize or pay for the denied service. The IRO’s decision is not a recommendation — it is final.
Deadline to file for external review: Under the federal baseline, you have 4 months (approximately 120 days) from the date of the final internal appeal denial notice. Some states impose shorter windows, and some allow longer. Check your denial notice for the specific deadline — it must be stated in the notice.
What the IRO reviews: The IRO reviews the medical records, the insurer’s clinical criteria, the treating physician’s documentation, and any peer-reviewed clinical literature you submit. IROs must be accredited by URAC or a similar nationally recognized accrediting organization. The plan may not choose an IRO that has a financial incentive to uphold denials.
Expedited external review: For urgent care situations — a NICU case where a service is needed before a standard review could be completed, for example — you can request expedited external review. The federal minimum timeline for expedited external review is 72 hours. This is the provision to know if your infant is hospitalized and the denial is affecting ongoing care.
As of January 1, 2026, new federal rules also require Medicare Advantage plans and Medicaid managed care plans to decide standard prior authorization requests within 7 calendar days and to provide a specific reason for every denial. This is a new procedural protection that may be relevant if your child is on Medicaid managed care.
Step 4: Additional escalation paths
If external review is exhausted or unavailable in your situation, additional options exist.
State insurance commissioner. If your plan is ACA-governed (fully insured), your state insurance commissioner has jurisdiction over the insurer. Filing a complaint with the state insurance department creates a regulatory record and sometimes triggers informal resolution. Find your state commissioner at NAIC’s consumer information page.
Department of Labor complaint (ERISA plans). For self-funded ERISA plans, the U.S. Department of Labor’s Employee Benefits Security Administration (EBSA) handles complaints. The EBSA has authority to investigate benefit denial practices. Contact information is at dol.gov/agencies/ebsa.
CMS complaint (Medicaid/Medicare Advantage). If the denied service is covered by Medicaid managed care or a Medicare Advantage plan, CMS has complaint procedures. CMS’s complaint information covers the federal framework.
Hospital patient advocates and social workers. If your infant is currently hospitalized, the hospital’s patient advocate or social worker can assist with real-time denial disputes. They have experience negotiating with insurers during active hospital stays and often have direct contacts within major insurers’ case management teams. Ask for a referral to the patient advocate department at admission or at any point during a hospitalization.
Tips for specific denial types
Medical necessity denials (most common): The key is a specific physician letter that addresses the insurer’s clinical criteria by name — not a general “I ordered this because it was needed” note. Ask your pediatrician to review the insurer’s clinical policy and respond to it directly.
Prior authorization denials (retroactive): If a service was provided in an emergency or urgent situation where getting prior authorization wasn’t possible, document why. Federal and most state laws require insurers to provide a post-service appeals process for services provided in genuine emergency circumstances.
NICU or inpatient denials: Concurrent review denials — where an insurer attempts to discharge or end authorization for an ongoing hospital stay — have expedited appeal rights. You do not need to wait until discharge to appeal. Request an expedited internal appeal immediately upon receiving a concurrent review denial. The 72-hour expedited timeline applies.
Out-of-network denials: If your infant required care at an out-of-network facility because no in-network facility could provide the required level of care (common in NICU situations in smaller markets), document that fact. Many states and the federal No Surprises Act provide consumer protections when no adequate in-network option is available.
What to do this week
If you’ve received a denial and are within the appeal window:
- Call member services and confirm you understand the denial reason code and your plan type (fully insured vs. self-funded).
- Request the complete denial notice in writing with the clinical criteria used.
- Contact your child’s treating provider and ask for a written letter of medical necessity specifically responding to the insurer’s stated rationale.
- Calculate your internal appeal deadline from the denial date (federal minimum: 180 days).
- Submit a complete written appeal with the physician letter and supporting records.
The Department of Labor’s claims and appeals guide and the CMS consumer appeals resource explain your federal rights in additional detail.
Frequently asked questions
Can I appeal a denial even if I’ve already paid the bill?
Yes. You can still appeal and seek reimbursement. The deadline runs from the denial date, not the payment date. If you paid out of pocket for a service that was denied, a successful appeal can result in reimbursement.
What if the insurer doesn’t respond to my internal appeal in time?
If the insurer fails to decide within the required timeline, that failure is treated as an adverse determination — meaning you can immediately proceed to external review as if your appeal was denied. Document the deadline and the absence of a response.
Can my pediatrician file the appeal on my behalf?
Your provider can assist with documentation and, in some cases, file an appeal as your authorized representative. Some insurers require a signed authorization form. The appeal on behalf of the patient is most effective when you are involved in crafting the arguments alongside the provider’s clinical documentation.
I’m not sure if the denial was for a covered service. How do I find out?
Request a copy of your plan’s Summary Plan Description — the full document, not the summary card. All covered and excluded services must be listed. If the service is covered by your plan but the insurer denied it for another reason (like medical necessity), you have the right to challenge that determination through the appeals process.
