By Counterforce Health Team in Crysvita (burosumab) —

Do You Qualify for Crysvita (burosumab) Coverage by Aetna (CVS Health) in Michigan? Decision Tree & Next Steps

Quick Answer: Your Path to Coverage

Yes, most Michigan patients with confirmed XLH or TIO can get Crysvita covered by Aetna (CVS Health), but prior authorization is always required. The fastest path: (1) Confirm genetic testing shows PHEX mutation or biochemical evidence of elevated FGF23 with low serum phosphorus, (2) Document failure/intolerance to oral phosphate plus vitamin D therapy, (3) Submit Aetna's precertification form via CVS Specialty at 1-866-814-5506. Standard decisions take 30-45 days. If denied, you have 180 days to appeal internally, then 127 days for Michigan's external review through DIFS.

Table of Contents

How to Use This Decision Tree

This guide helps Michigan patients and their clinicians determine if Crysvita (burosumab) will likely be covered by Aetna (CVS Health), what documentation you'll need, and how to navigate denials. Start with the eligibility triage below to see where you stand.

Note: This is not medical advice. Always work with your healthcare provider to determine the best treatment approach for your condition.

Eligibility Triage: Do You Qualify?

Answer These Questions:

1. Do you have a confirmed diagnosis?

  • ✅ XLH: Genetic testing confirms PHEX mutation OR elevated FGF23 with low serum phosphorus and bone disease
  • ✅ TIO: Elevated FGF23, low fasting serum phosphorus, with unresectable/unlocalized tumor
  • ❌ Suspected but not confirmed

2. Are you the right age?

  • ✅ XLH: 6 months or older
  • ✅ TIO: 2 years or older
  • ❌ Below age requirements

3. Have you tried conventional therapy?

  • ✅ Failed, had intolerance, or contraindication to oral phosphate + active vitamin D for at least 6 months
  • ❌ Haven't tried conventional therapy yet
  • ❌ Currently taking oral phosphate or active vitamin D

4. Do you have required labs?

  • ✅ Current fasting serum phosphorus below normal for age
  • ✅ FGF23 level (elevated)
  • ❌ Missing key lab work

Your Results:

All ✅ = Likely Eligible → Go to If You're Likely Eligible

Mostly ✅ with 1-2 ❌ = Possibly Eligible → Go to If You're Possibly Eligible

Several ❌ = Not Yet Eligible → Go to If You're Not Yet Eligible

If You're Likely Eligible

Document Checklist

Gather these items before submitting your prior authorization:

Document What You Need Where to Get It
Genetic Testing PHEX mutation results OR family history with X-linked pattern Genetics lab, previous testing
Lab Results Fasting serum phosphorus (below normal), elevated FGF23, alkaline phosphatase Your clinic's lab
Imaging Studies X-rays showing rickets/osteomalacia, DEXA scans if available Radiology department
Treatment History Documentation of oral phosphate + vitamin D trial, failure/intolerance notes Medical records
Provider Attestation Confirmation you're not taking oral phosphate or active vitamin D Your prescriber

Submission Path

Step 1: Have your prescriber complete Aetna's Crysvita precertification form.

Step 2: Submit via CVS Specialty:

  • Phone: 1-866-814-5506 (fastest)
  • Fax: 1-866-249-6155
  • Online: Through Aetna provider portal

Step 3: Track your request weekly. Standard decisions take 30-45 days.

Tip: Call CVS Specialty every Friday to check status. Get a reference number for your submission.

If You're Possibly Eligible

Tests to Request

Missing genetic confirmation?

  • Request PHEX gene sequencing from genetics lab
  • Alternative: Document family history showing X-linked inheritance pattern

Missing lab work?

  • Fasting serum phosphorus (must be below normal range)
  • FGF23 level (should be elevated)
  • 24-hour urine phosphorus or TmP/GFR ratio
  • Baseline kidney function (creatinine clearance)

Missing imaging?

  • X-rays of bones showing rickets or osteomalacia
  • DEXA scan if available

Timeline to Re-apply

Allow 2-4 weeks to gather missing documentation, then submit. Don't delay—Aetna's criteria are strict and complete applications process faster.

If You're Not Yet Eligible

Alternatives to Discuss with Your Doctor

For XLH or TIO without prior conventional therapy:

  1. Trial of oral phosphate + calcitriol/alfacalcidol for 6+ months
  2. Document response, side effects, or reasons for discontinuation
  3. Important: Stop these medications before starting Crysvita (contraindicated)

For TIO with localized tumor:

  • Surgical resection remains first-line treatment
  • Crysvita only covered if tumor is unresectable or unlocalized

Prepare for Exception Requests

If conventional therapy isn't appropriate, your doctor can request a formulary exception through Aetna's medical exception process:

  • Phone: 1-800-294-5979 (non-specialty) or 1-866-814-5506 (specialty)
  • Fax: Medical exception form to 1-866-249-6155
  • Required: Detailed medical rationale for why conventional therapy is contraindicated

If You've Been Denied

First-Level Appeal (Internal)

Timeline: File within 180 days of denial notice

How to file:

  • Online: Aetna member portal
  • Phone: Number on your denial letter
  • Mail: Address provided in denial notice

What to include:

  • Copy of denial letter
  • Additional medical records
  • Updated lab results
  • Provider letter addressing specific denial reasons

Peer-to-Peer Review

Request your doctor call Aetna's medical director:

  • Phone: 1-855-240-0535 (Monday-Friday, 8 AM-6 PM Central)
  • Purpose: Direct physician discussion about medical necessity

Counterforce Health helps patients, clinicians, and specialty pharmacies get prescription drugs approved by turning insurance denials into targeted, evidence-backed appeals. The platform analyzes denial letters and creates point-by-point rebuttals aligned to each insurer's specific policies, pulling the right medical evidence and clinical facts needed for successful appeals. Learn more at counterforcehealth.org.

Expedited Appeals

When to request: If delay would seriously jeopardize your health Timeline: Decision within 72 hours Required: Physician letter stating urgency

Michigan Appeal Rights

External Review Through DIFS

If Aetna upholds their denial after internal appeal, Michigan patients have strong external review rights:

Timeline: 127 days after final internal denial to file with Michigan DIFS

How to file:

Process:

  • DIFS assigns Independent Review Organization (IRO)
  • Standard decision: 60 days maximum
  • Expedited decision: 72 hours (with physician urgency letter)
  • No cost to patient
  • Binding decision: If overturned, Aetna must provide coverage
From our advocates: We've seen Michigan patients successfully overturn Aetna denials for rare disease medications by ensuring their external review submission included both the genetic testing results and clear documentation of conventional therapy failure. The key is presenting a complete clinical picture that directly addresses each denial reason listed in Aetna's policy.

Resources & Next Steps

Key Contacts

Need Contact Phone
CVS Specialty (PA submission) Prior authorization 1-866-814-5506
Aetna Member Services Coverage questions Number on your ID card
Michigan DIFS External appeals 877-999-6442
Counterforce Health Appeal assistance counterforcehealth.org

Cost Support Options

Manufacturer Programs:

  • Ultracare: Patient assistance from Ultragenyx
  • Copay support: May reduce out-of-pocket costs (verify eligibility)

Foundation Grants:

  • The Assistance Fund and other rare disease foundations may help with costs

Documentation You'll Need

Before starting:

  • Insurance card with member ID
  • Complete medical records
  • All lab results (especially phosphorus, FGF23)
  • Imaging studies
  • Prior therapy documentation

FAQ

How long does Aetna prior authorization take in Michigan? Standard decisions take 30-45 days after complete submission. Expedited requests (urgent medical need) are decided within 24 hours.

What if Crysvita is non-formulary on my plan? You can request a formulary exception with medical justification. The process is similar to prior authorization but requires stronger clinical rationale.

Can I request an expedited appeal if denied? Yes, if your physician certifies that waiting would seriously jeopardize your health. Both Aetna's internal expedited appeal and Michigan's external expedited review are available.

Does step therapy apply if I failed conventional therapy outside Michigan? Yes, Aetna accepts documentation of prior therapy failure from any location, as long as it's properly documented in your medical records.

What counts as "failure" of conventional therapy? Lack of biochemical improvement, continued bone pain, fractures, dental problems, or intolerable side effects (GI issues, kidney problems) after at least 6 months of adequate dosing.

How much will Crysvita cost with Aetna coverage? This varies by plan, but typically it's covered as a specialty medication with 20-40% coinsurance after deductible. Verify your specific costs with CVS Specialty.

Sources & Further Reading

Disclaimer: This guide provides educational information about insurance coverage processes and should not replace professional medical advice. Always consult with your healthcare provider about treatment decisions. For specific coverage questions, contact Aetna directly using the numbers on your insurance card. Michigan residents can get free help with insurance appeals through DIFS at 877-999-6442.

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