By Counterforce Health Team in Enhertu (fam-trastuzumab deruxtecan-nxki) —

How to Get Enhertu (fam-trastuzumab deruxtecan-nxki) Covered by Blue Cross Blue Shield in New York: Complete Prior Authorization and Appeal Guide

Quick Answer: Getting Enhertu Covered by BCBS in New York

Enhertu (fam-trastuzumab deruxtecan-nxki) requires prior authorization from Blue Cross Blue Shield plans in New York for HER2-positive breast cancer, NSCLC, and gastric cancer. Key requirements include documented HER2 status (IHC 3+ or ISH amplified), prior trastuzumab-based therapy failure, and NCCN guideline support. Submit PA via your provider's portal with medical necessity letter, HER2 testing results, and treatment history. Standard review takes 14 days; expedited decisions in 72 hours. If denied, New York offers strong external appeal rights through the Department of Financial Services within 4 months of final denial.

Start today: Call the member services number on your insurance card to confirm your specific BCBS plan and formulary tier for Enhertu.

Table of Contents

Understanding BCBS Coverage for Enhertu

Blue Cross Blue Shield plans in New York include multiple independent affiliates—primarily Anthem Blue Cross Blue Shield, Excellus BlueCross BlueShield, and Highmark Blue Shield (western NY). Each maintains separate formularies but follows similar prior authorization protocols for specialty oncology drugs like Enhertu.

Coverage at a Glance

Requirement What It Means Where to Find It Source
Prior Authorization Required before first infusion Provider portal or CoverMyMeds BCBS Policy
Formulary Tier Tier 3+ (higher copay) Formulary Navigator Anthem NY
HCPCS J-Code J9358 (1 unit = 1 mg) Medical benefit billing AAPC Codes
Site of Care Oncology clinic/infusion center PA form specification BCBS Policy
Appeal Deadline 4 months for external review After final internal denial NY DFS

Prior Authorization Requirements by Cancer Type

BCBS plans require specific documentation based on your cancer diagnosis. Here's what your oncologist needs to include:

HER2-Positive Breast Cancer (Unresectable/Metastatic)

  • HER2 Status: IHC 3+ or ISH amplified (≥4.0-6.0 signals/cell)
  • Prior Therapy: Progression or intolerance on ≥1 trastuzumab-based regimen
  • Cardiac Function: LVEF ≥50% within 3 months
  • ICD-10 Codes: Primary C50.- (breast site) + Z17.410 (HR+/HER2+) or Z17.420 (HR-/HER2+)

HER2-Mutant NSCLC (Non-Small Cell Lung Cancer)

  • Mutation Testing: Confirmed HER2 exon 20 insertion or activating mutation
  • Prior Treatment: At least one prior systemic therapy
  • Performance Status: ECOG 0-2 documented
  • ICD-10 Code: C34.- (lung primary site)

HER2-Positive Gastric/GEJ Adenocarcinoma

  • HER2 Status: IHC 3+ or ISH amplified per FDA labeling
  • NCCN Support: Category 1 or 2A recommendation
  • Prior HER2 Therapy: Progression on trastuzumab-based treatment
  • ICD-10 Code: C16.- (gastric) or C16.0 (gastroesophageal junction)
Tip: Request HER2 testing reports with specific scoring methodology. Equivocal results (IHC 2+) require ISH confirmation for approval.

Step-by-Step Approval Process

1. Verify Insurance and Formulary Status

Who does it: Patient or clinic staff
Timeline: Same day
Call the member services number on your insurance card. Ask specifically:

  • Which BCBS plan you have (Anthem, Excellus, or Highmark)
  • Enhertu's formulary tier and copay
  • Prior authorization requirements
  • Preferred infusion sites

2. Gather Required Documentation

Who does it: Oncology team
Timeline: 3-5 business days
Collect these documents before PA submission:

  • Pathology report with HER2 testing methodology and results
  • Treatment history documenting prior trastuzumab exposure
  • Recent ECHO or MUGA showing LVEF ≥50%
  • Staging scans confirming unresectable/metastatic disease
  • NCCN guideline reference for your specific indication

3. Submit Prior Authorization

Who does it: Prescribing oncologist
Timeline: Submit 5-7 days before planned infusion
Use your provider's preferred method:

Include a medical necessity letter addressing:

  • FDA-approved indication
  • Failed prior therapies with dates and reasons for discontinuation
  • HER2 testing methodology and results
  • NCCN Category 1/2A support
  • Monitoring plan for interstitial lung disease (ILD)

4. Track Decision and Follow Up

Who does it: Clinic staff
Timeline: Check status after 48-72 hours

  • Standard PA decisions: 14 calendar days
  • Expedited reviews: 72 hours (for urgent cases)
  • Log into provider portal or call PA hotline for status updates

When Counterforce Health helps practices with complex prior authorizations like Enhertu, they've found that including specific NCCN guideline citations and detailed prior therapy timelines significantly improves approval rates. Their platform automatically identifies the denial basis and crafts targeted rebuttals aligned to each payer's specific criteria.

Coding and Billing Essentials

Medical vs. Pharmacy Benefit

Enhertu is billed under the medical benefit as a physician-administered infusion, not through pharmacy benefits. This means:

  • Use HCPCS J-code J9358 for billing
  • Submit through medical claims, not prescription benefits
  • Requires infusion administration codes (CPT 96413/96415)

HCPCS and Billing Units

  • J-Code: J9358 (permanent code effective July 1, 2020)
  • Unit Definition: 1 unit = 1 mg administered
  • Dosing Calculation: 5.4 mg/kg IV every 3 weeks
    • Example: 70 kg patient = 378 mg = 378 billable units
  • NDC Code: 65597-0406-01 with "UN1" units

ICD-10 Documentation Requirements

Proper diagnosis coding supports medical necessity:

Cancer Type Primary ICD-10 Secondary Codes Documentation
HER2+ Breast C50.- (specific site) Z17.410 or Z17.420 HER2 IHC/ISH results
HER2-mutant NSCLC C34.- (lung site) None specific Mutation testing report
HER2+ Gastric C16.- (gastric site) None specific HER2 testing methodology

Common Billing Errors to Avoid

  • Unit Conversion Mistakes: Always bill per mg, not per vial
  • Missing Modifiers: Include KX modifier for Medicare LCD compliance
  • Wrong Administration Code: Use 96413 for initial hour, 96415 for additional
  • Date Mismatches: Ensure billing date matches actual infusion date

Common Denial Reasons and Solutions

Based on BCBS policy analysis, here are frequent denial triggers and fixes:

Denial Reason Solution Required Documentation
Missing HER2 status Submit complete pathology report IHC scoring methodology, ISH results if applicable
Insufficient prior therapy Document trastuzumab exposure Treatment dates, response, reason for discontinuation
Not medically necessary Strengthen clinical rationale NCCN guidelines, FDA labeling citations
Site of care restriction Justify infusion location Clinic accreditation, patient access needs
Experimental/investigational Cite FDA approval FDA label for specific indication
From our advocates: We've seen denials overturned when providers include the exact NCCN guideline version and page number supporting Enhertu use. This level of specificity demonstrates thorough clinical review and often satisfies medical necessity requirements.

Appeals Process in New York

New York offers robust appeal rights through multiple pathways:

Internal Appeal (First Level)

  • Timeline: File within 180 days of denial
  • Decision: 30 days (15 for urgent)
  • How to File: Provider portal, mail, or fax per EOB instructions
  • Required: Original PA documents plus new supporting evidence

External Review (New York DFS)

  • Timeline: File within 4 months of final internal denial
  • Decision: 45 days (72 hours for urgent)
  • Cost: $25 fee (waived for Medicaid/financial hardship)
  • How to File: NY DFS External Appeal Portal

Expedited Appeals

For urgent cases where delays could seriously jeopardize your health:

  • Timeline: 24-72 hours for decision
  • Criteria: Immediate treatment needed
  • Documentation: Physician statement of urgency

Appeal Script for Patients

When calling BCBS member services:

"I'm calling about a denied prior authorization for Enhertu (fam-trastuzumab deruxtecan-nxki) for my HER2-positive [cancer type]. I need to understand the specific denial reason and how to file an internal appeal. Can you provide the appeal form and submission instructions? I also need to know the deadline for filing."

Cost Assistance Programs

Manufacturer Support

  • Daiichi Sankyo Patient Assistance: Income-qualified patients may receive free medication
  • Copay Card: Up to $25,000 annual benefit for commercially insured patients
  • Information: Enhertu Support Program (verify current links)

Foundation Grants

  • Patient Access Network (PAN): Copay assistance for specific cancer types
  • CancerCare: Financial assistance and case management
  • Leukemia & Lymphoma Society: Patient aid program

New York State Programs

  • Medicaid: Covers Enhertu with PA for eligible patients
  • Essential Plan: Low-cost option for those above Medicaid limits
  • EPIC: Prescription assistance for seniors

Organizations like Counterforce Health specialize in turning insurance denials into successful appeals by identifying the specific denial basis and crafting evidence-backed rebuttals. Their platform helps patients and providers navigate complex prior authorization requirements more efficiently.

Frequently Asked Questions

How long does BCBS prior authorization take for Enhertu in New York? Standard PA decisions take up to 14 calendar days. Expedited reviews for urgent cases are completed within 72 hours. Submit PA requests 5-7 days before planned treatment.

What if Enhertu is non-formulary on my BCBS plan? Request a formulary exception with documentation of failed alternatives and medical necessity. Include NCCN guideline support and prior therapy history.

Can I get an expedited appeal if treatment is urgent? Yes. New York allows expedited external appeals with decisions in 24-72 hours if delays could seriously jeopardize your health. Your oncologist must document the urgency.

Does step therapy apply if I failed trastuzumab outside New York? Prior therapy failures from any location count toward step therapy requirements. Provide complete treatment records with dates and reasons for discontinuation.

What's the maximum out-of-pocket cost for Enhertu? Costs vary by plan. Commercial insurance copays can be substantial, but manufacturer copay cards may reduce costs to $5-$25 per infusion for eligible patients.

Who can help if my appeal is denied? Contact Community Health Advocates at 888-614-5400 for free assistance with New York insurance appeals. They can help file external reviews with NY DFS.

How do I verify my BCBS plan's specific Enhertu policy? Use the Formulary Navigator to search your plan's coverage. Enter "Enhertu" to see tier, PA requirements, and restrictions.

What happens if external review upholds the denial? External review decisions are binding, but you may have options through state insurance regulators if proper procedures weren't followed. Contact NY DFS for guidance.

Sources and Further Reading

Disclaimer: This information is for educational purposes only and does not constitute medical or legal advice. Coverage policies vary by specific insurance plan and are subject to change. Always verify current requirements with your insurance provider and consult your healthcare team for medical decisions. For personalized assistance with insurance denials and appeals, contact qualified patient advocates or legal professionals.

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