The letter usually says something like “not medically necessary” or “services exceed authorized limit,” and it can feel like a full stop right when you’d finally gotten your child’s care moving. It isn’t a full stop.
Colorado gives you a real, structured right to appeal an ABA therapy claim denial, and a meaningful share of denials get reversed once families understand exactly what the process asks of them. I’ll walk you through what to do next, step by step, whether you’re on a private plan like Aetna, Cigna, or Anthem, or on Health First Colorado, Colorado’s Medicaid program.
One note before we start: this blog explains the general process, but the specific rules that apply to your situation are in your denial letter and your plan documents, so always follow those instructions first. If you’d rather have someone walk your specific appeal for you, our ABA therapy insurance team deals with exactly this kind of denial regularly, but if you want to understand the process yourself first, here’s exactly how it works.
Why ABA Therapy Claims Get Denied in the First Place
A denial letter rarely explains itself in plain language. Knowing the common reasons behind it helps you figure out quickly which kind of appeal you’re actually building.
The Most Common Denial Reasons
- The evaluation didn’t clearly document medical necessity for the specific hours requested
- Prior authorization was never obtained before services started
- The number of hours requested exceeds what the plan considers typical without more justification
- Paperwork was incomplete, expired, or sent to the wrong department
- The plan questions whether ABA is medically necessary versus an educational service, a distinction insurers sometimes draw incorrectly
- An authorization period expired before renewal paperwork was submitted
In sessions across Denver, the single most common reason we see is the first one on that list: a strong clinical need that simply wasn’t documented in the language the insurer’s review criteria are looking for.
A Denial Is Not Usually the Final Word
For Health First Colorado specifically, Colorado’s own legislative oversight data gives a clear picture. In 2024 and 2025, the state fully approved between 92 and 93 percent of prior authorization requests and fully denied about 7 percent. Of the appeals that made it to a formal hearing, close to one in four ended with the original Medicaid decision reversed.
That’s not a guarantee for any individual case, and appeals still take real documentation and real time, but it does mean the process is a genuine avenue rather than a formality. Families in Aurora and across the state file these appeals successfully every year.
The Two Very Different Appeal Paths in Colorado
We accept both private insurance and Health First Colorado, and the appeal process is genuinely different depending on which one your family has. Getting this part right up front saves weeks.
Private Insurance: Aetna, Cigna, Anthem, and Similar Plans
For private plans, Colorado’s Division of Insurance oversees a two-step appeal process: an internal appeal directly with your insurer, followed by an independent external review if the internal appeal doesn’t change the outcome. We work directly with plans like Aetna and Cigna, and the same basic process applies to Anthem, UMR, and most other private plans we accept.
If you want to see how these plans compare on ABA coverage specifically, our breakdown of Aetna, Cigna, and Medicaid coverage walks through the differences. In our Colorado Springs office, this is the path most of the families we work with are on.
Health First Colorado and CHP+ (Medicaid)
Medicaid works through a different system entirely: a state fair hearing in front of an administrative law judge at Colorado’s Office of Administrative Courts, not an internal insurance company review. If your family also draws on a Medicaid waiver for additional support beyond standard coverage, our guide to Colorado Medicaid waivers explains how those extra benefits interact with your child’s core coverage. We see this path most often with families in Lakewood and other communities where Health First Colorado is the primary coverage.
Step 1: Read the Denial Letter Line by Line
Before you write anything, the letter itself tells you what kind of appeal you’re building and how much time you have to build it.
What the Letter Has to Tell You
- The specific reason for the denial, in the insurer’s own words
- Which clinical criteria or plan provision was applied
- Your deadline to file an internal appeal
- Instructions for exactly how and where to submit it
Mark Your Deadline Immediately
For most private plans in Colorado, you generally have 180 days from the date of the denial to request an internal appeal. For Health First Colorado, that window is much shorter: 60 days from the date on your Notice of Action to request a state fair hearing, and only 10 days if you want your child’s current services to continue unchanged while the appeal is pending.
Families in Fort Collins and everywhere else in the state are held to these same windows, so write the date down somewhere you’ll actually see it again.
Step 2: Build Your Appeal File Before You Write Anything
The strongest appeals lead with documentation, not emotion, even though the emotion behind them is completely justified.
Documents That Actually Move the Needle
- Your child’s full diagnostic evaluation
- The BCBA’s treatment plan and clinical justification for the specific hours requested
- Progress data from current or previous ABA services, if available
- The original denial letter and any prior correspondence
- A copy of your plan’s coverage language for autism or ABA services, if you can find it
Getting the Right Paperwork From Us
If your child is already receiving services through us, we can pull your clinical documentation and treatment plan directly. Families in Pueblo and other communities we serve can also request an updated diagnostic evaluation if something in the original documentation was thin or if your child’s needs have changed since the last one.
Step 3: File the Internal Appeal
This is the step most families get right about the deadline and wrong about the content. A letter that just says “please reconsider” rarely moves anything.
What to Say in a Private Insurance Appeal Letter
Reference the specific clinical criteria the insurer cited in its denial, and respond to that criteria directly rather than restating your child’s diagnosis in general terms. State the exact number of hours the evaluation supports, attach the treatment plan and any progress data, and quote the specific plan language that covers ABA services if you have it. Families in Thornton who’ve gone through this successfully almost always did this one thing well: they made the appeal easy for a reviewer to say yes to, instead of making the reviewer do the work of connecting the dots.
What to Say in a Health First Colorado Appeal
For a Medicaid appeal, you’re writing to the Office of Administrative Courts to request a state fair hearing, not to the health plan itself. Include a copy of your Notice of Action, you
r name and Health First Colorado member ID, and a clear, specific explanation of why you disagree with the decision. You do not need a lawyer to do this, and you can bring a provider, advocate, or family member to represent you at the hearing if you’d rather not go alone.
Step 4: If the Internal Appeal Doesn’t Work
An internal appeal denial isn’t the end of the process for either type of coverage, though the next step looks different depending on which path you’re on.
External Review for Private Insurance
Colorado’s Division of Insurance assigns an independent, certified external reviewer once your internal appeal is exhausted. You generally have four months after a first-level appeal decision, or 60 days after an optional second-level review, to request it, and the external reviewer has 45 days to issue a written decision once assigned.
If the external reviewer sides with you, your insurer has to approve the covered services according to your plan’s terms, a path several families we work with in Westminster have used successfully after an initial denial.
Requesting a State Fair Hearing for Medicaid
For Health First Colorado, if your appeal with the health plan doesn’t resolve things, you can request a formal state fair hearing with the Office of Administrative Courts. An administrative law judge typically issues an initial decision within about 20 days of the hearing, and either side can file a written exception within 18 days if they disagree with that initial decision. A final agency decision usually follows within 90 days of the original hearing request.
What to Do While You Wait
Appeals take real time, and knowing what happens to your child’s care in the meantime matters just as much as the paperwork itself.
Can Therapy Continue During an Appeal?
For Health First Colorado, if the appeal is about a service that was already authorized and is now being reduced or stopped, and you request your hearing within 10 days of the notice, your child’s current services generally continue until the appeal is decided. Requesting a brand-new service that gets denied doesn’t carry that same continuation right. Private plans don’t guarantee automatic continuation the same way, so it’s worth asking your insurer this question directly and getting the answer in writing.
Getting Help If You Feel Stuck
Families in Arvada and elsewhere in Colorado can get free help with a Medicaid appeal through Colorado Legal Services or the Colorado Cross-Disability Coalition, and Health First Colorado’s own Member Contact Center can answer questions about where your appeal stands. You don’t have to have a lawyer to appeal successfully, and you’re allowed to ask for help at any point in the process.
Getting Support With Insurance and Appeals in Colorado
If everything above feels like a lot to manage on top of everything else on your plate, that’s a completely reasonable reaction, and it’s exactly why this part of our work exists.
How We Help With the Process
Our team verifies benefits before you commit to anything, submits and follows up on every authorization ourselves, and handles claims, resubmissions, and appeals directly with your insurance company when coverage gets denied. If insurance won’t cover the hours your child needs even after an appeal, it’s also worth understanding what your school district may separately be required to provide, and our comparison of private and public school special education option breaks down how that funding works alongside insurance.
We work with families throughout the state, including in Centennial and Boulder, in addition to the communities mentioned earlier.
You don’t have to build that case alone. If you’ve received a denial and aren’t sure what to do with it, reach out to our Colorado team. We’ll help you understand exactly where you stand and what the next step should be.
Frequently Asked Questions
How long does an ABA therapy appeal take in Colorado?
It varies by plan and by path. A private insurance internal appeal decision typically comes within 30 to 60 days, with external review adding up to 45 more days once assigned. A Health First Colorado state fair hearing usually results in an initial decision within about 20 days of the hearing itself, though scheduling the hearing can take longer depending on demand.
What if my child’s authorization expires while we’re appealing?
Let your care team know immediately. For Health First Colorado, requesting your hearing within 10 days of a reduction or termination notice generally keeps existing services in place until a decision is made. For private plans, ask your insurer directly whether your specific denial qualifies for continued services during the appeal, since this isn’t guaranteed the same way across every plan.
Can I appeal more than once?
For private insurance, you typically get one internal appeal per denied claim, followed by one external review if the internal appeal doesn’t resolve it. For Health First Colorado, if you disagree with the administrative law judge’s initial decision, you can file a written exception within 18 days asking the Office of Appeals to reconsider before a final agency decision is issued.
Do I need a lawyer to appeal an insurance denial?
No. Both the private insurance appeal process and the Health First Colorado state fair hearing process are designed for people to use without an attorney, and organizations like Colorado Legal Services and the Colorado Cross-Disability Coalition offer free help if you want support without hiring anyone.
What if I have both private insurance and Medicaid?
This is common, and it usually means private insurance is billed first, with Health First Colorado covering costs your primary plan doesn’t. If a claim is denied, you may need to appeal with your primary insurer first before Medicaid’s process becomes relevant, so it’s worth asking our insurance team to walk through your specific situation.
This guide reflects Colorado’s general appeal process as of publication. Deadlines, forms, and requirements can change, and your specific denial letter always takes precedence, so confirm details there before you file.
Sources:
- Colorado Division of Insurance, “When Your Health Insurance Company Says No”: https://www.healthfirstcolorado.gov/benefits-services/appeals/
- Health First Colorado, Appeals https://www.healthfirstcolorado.gov/benefits-services/appeals/
- Colorado Legislative Council Staff, Medicaid Appeals in Colorado (2026) https://content.leg.colorado.gov/sites/default/files/R25-995_Medicaid%20Appeals%20in%20Colorado.pdf