By Counterforce Health Team in Carbaglu (carglumic acid) —

How to Get Carbaglu (Carglumic Acid) Covered by Humana in California: Complete PA Guide with Appeals Process

Answer Box: Getting Carbaglu Covered by Humana in California

Fastest Path to Approval: Submit prior authorization with confirmed NAGS deficiency diagnosis (ICD-10: E72.2), ammonia levels, and genetic/enzymatic testing results. Use HCPCS J7518 for billing (100mg units). If denied, file internal appeal within 65 days, then request California Independent Medical Review (IMR) through DMHC for binding external review.

First Step Today: Call Humana Clinical Pharmacy Review at 800-555-CLIN (2546) to confirm PA requirements and obtain forms. Have your member ID, prescriber information, and diagnosis ready.

Table of Contents

  1. Coverage Requirements Overview
  2. Medical vs. Pharmacy Benefit Pathways
  3. Essential ICD-10 and Diagnostic Coding
  4. HCPCS J-Code and NDC Billing Details
  5. Step-by-Step Prior Authorization Process
  6. Common Denial Reasons and Solutions
  7. Appeals Process: Internal to IMR
  8. Cost and Patient Assistance Options
  9. Frequently Asked Questions

Coverage Requirements Overview

Carbaglu (carglumic acid) requires prior authorization through most Humana plans, including Medicare Advantage and Part D coverage. The medication treats acute and maintenance hyperammonemia due to N-acetylglutamate synthase (NAGS) deficiency and certain organic acidemias.

Requirement What It Means Where to Find It
Prior Authorization Pre-approval needed before dispensing Humana Provider Portal
Medical Necessity Confirmed NAGS deficiency or organic acidemia FDA prescribing information, genetic testing
Step Therapy May require trial of alternatives first Plan-specific formulary documents
Quantity Limits Dosing based on weight and ammonia levels FDA Carbaglu Label
Note: Humana has committed to reducing prior authorization requirements by approximately one-third by January 2026, though specialty medications like Carbaglu may still require review.

Medical vs. Pharmacy Benefit Pathways

Understanding whether Carbaglu falls under medical (Part B) or pharmacy (Part D) benefits affects your approval pathway:

Medical Benefit (Part B) Scenarios:

  • Hospital outpatient administration
  • Physician office infusion centers
  • Acute hyperammonemia management
  • Uses HCPCS J7518 billing code

Pharmacy Benefit (Part D) Scenarios:

  • Home administration via oral tablets
  • Long-term maintenance therapy
  • Retail or specialty pharmacy dispensing
  • Uses NDC codes for billing

Most Carbaglu prescriptions fall under pharmacy benefits since the medication is administered orally at home. However, acute episodes requiring immediate treatment may qualify for medical benefit coverage.

Essential ICD-10 and Diagnostic Coding

Proper diagnostic coding is crucial for Carbaglu approval. The primary diagnosis code is E72.2 - Disorders of urea cycle metabolism, which covers NAGS deficiency.

Supporting Documentation Keywords:

  • "Biochemically confirmed NAGS deficiency"
  • "Elevated ammonia levels (>50 μmol/L)"
  • "Genetic testing positive for NAGS gene mutations"
  • "Enzymatic activity testing on liver biopsy"
  • "Therapeutic response to N-carbamylglutamate"

Related ICD-10 Codes:

  • E71.121: Methylmalonic acidemia
  • E71.118: Other branched-chain organic acidurias
  • E71.111: 3-methylglutaconic aciduria
Clinician Corner: Document the specific metabolic pathway disruption and include baseline ammonia levels, genetic test results, and any prior treatment failures with nitrogen scavengers or dietary protein restriction.

HCPCS J-Code and NDC Billing Details

HCPCS J-Code: J7518 represents carglumic acid oral 100 mg per billing unit.

NDC Codes:

  • 52276-312-05: Bottle of 5 tablets (200 mg each)
  • 52276-312-60: Bottle of 60 tablets (200 mg each)

Dosing and Unit Calculations:

Patient Weight Daily Dose (mg/kg) Total Daily Dose Billing Units (J7518)
20 kg child 100-250 mg/kg 2000-5000 mg 20-50 units
70 kg adult 100 mg/kg 7000 mg 70 units

Common Billing Pitfalls:

  • Confusing 200 mg tablets with 100 mg billing units
  • Missing weight-based calculations in PA requests
  • Incorrect units for maintenance vs. acute dosing

Step-by-Step Prior Authorization Process

Step 1: Gather Required Documentation

Who: Prescriber's office Timeline: 1-2 days

  • Confirmed NAGS deficiency diagnosis
  • Ammonia levels (baseline and during episodes)
  • Genetic testing results
  • Prior treatment history

Step 2: Submit PA Request

Who: Prescriber or authorized staff How: Humana Provider Portal or fax Timeline: Same day submission

Step 3: Humana Review Process

Timeline: 7 calendar days for standard review Expedited: 72 hours for urgent cases Decision: Approval, denial, or request for additional information

Step 4: If Approved - Prescription Processing

Timeline: 24-48 hours for specialty pharmacy Who: Patient coordinates with designated pharmacy

Step 5: If Denied - Begin Appeal Process

Timeline: Must appeal within 65 days Next Steps: Internal appeal, then external review if needed

Tip: Request expedited review for acute hyperammonemia cases by indicating "urgent medical necessity" and providing current ammonia levels.

Common Denial Reasons and Solutions

Denial Reason Solution Strategy Required Documentation
Diagnosis not confirmed Submit genetic testing DNA analysis showing NAGS mutations
Missing baseline labs Provide ammonia levels Lab results showing hyperammonemia
Step therapy required Document contraindications Prior failures with sodium phenylbutyrate
Quantity exceeds limits Justify weight-based dosing Body weight, BSA calculations
Off-label use concerns Cite FDA indications FDA prescribing information

Medical Necessity Letter Essentials:

  1. Specific metabolic defect (NAGS enzyme deficiency)
  2. Clinical presentation (hyperammonemia episodes)
  3. Diagnostic confirmation (genetic/enzymatic testing)
  4. Prior treatment failures or contraindications
  5. Expected outcomes with Carbaglu therapy

Appeals Process: Internal to IMR

Internal Appeal with Humana

Timeline: 65 days from denial to file appeal Process: Submit redetermination request with additional clinical evidence Decision: 7 days for standard, 72 hours for expedited

California Independent Medical Review (IMR)

If Humana upholds the denial, California residents can request external review through the Department of Managed Health Care (DMHC).

How to Request IMR:

  1. File grievance with Humana first (required)
  2. Wait 30 days or receive final denial
  3. Submit IMR application to DMHC
  4. Independent physicians review case
  5. Binding decision within 45 days (7 days if expedited)

Contact Information:

  • DMHC Help Center: 888-466-2219
  • Online application: healthhelp.ca.gov
  • No cost to patient for IMR process
From Our Advocates: We've seen success with IMR appeals when families include detailed treatment timelines showing how quickly ammonia levels normalize with Carbaglu compared to other interventions. The independent reviewers particularly value seeing objective lab improvements tied directly to the medication.

Counterforce Health helps patients navigate these complex appeal processes by analyzing denial letters, identifying specific coverage criteria, and drafting evidence-backed appeals that address each payer's requirements. Our platform streamlines the documentation process and tracks critical deadlines to maximize approval chances.

Cost and Patient Assistance Options

Manufacturer Support:

  • Recordati Rare Diseases Patient Assistance Program
  • Eligibility based on income and insurance status
  • Contact: Carbaglu.com patient resources

Copay Assistance:

  • May reduce out-of-pocket costs for commercially insured patients
  • Not applicable to Medicare Part D coverage
  • Income and insurance restrictions apply

Foundation Grants:

  • National Organization for Rare Disorders (NORD)
  • HealthWell Foundation rare disease fund
  • Patient Advocate Foundation copay relief

Frequently Asked Questions

Q: How long does Humana prior authorization take for Carbaglu? A: Standard review takes 7 calendar days. Expedited review for urgent cases is completed within 72 hours when medical urgency is documented.

Q: What if Carbaglu is not on Humana's formulary? A: You can request a formulary exception through the same PA process. Include documentation that formulary alternatives are ineffective or contraindicated for NAGS deficiency.

Q: Can I get expedited appeal in California? A: Yes, both Humana internal appeals and California IMR offer expedited processing for urgent medical situations involving current hyperammonemia or risk of metabolic decompensation.

Q: Does step therapy apply if I've used Carbaglu before? A: Prior successful treatment with Carbaglu may exempt you from step therapy requirements. Document previous response and any treatment gaps in your PA request.

Q: What happens if Humana denies my appeal? A: California residents can request Independent Medical Review through DMHC. The external review decision is binding on Humana and has favorable overturn rates for medically necessary treatments.

Q: How do I prove medical necessity for NAGS deficiency? A: Provide genetic testing confirming NAGS mutations, elevated ammonia levels during episodes, and documentation of therapeutic response to N-carbamylglutamate therapy.

Disclaimer: This information is for educational purposes and does not constitute medical advice. Coverage decisions depend on individual circumstances and specific plan benefits. Consult your healthcare provider and insurance plan for personalized guidance.

For additional help with insurance appeals and coverage issues, contact California's Department of Managed Health Care Help Center at 888-466-2219 or visit healthhelp.ca.gov.

When facing complex prior authorization requirements or denials, Counterforce Health provides specialized support for rare disease medication appeals, helping patients and providers build stronger cases with targeted clinical evidence and payer-specific strategies.

Sources & Further Reading

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