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

The Requirements Checklist to Get Enhertu (fam-trastuzumab deruxtecan-nxki) Covered by Blue Cross Blue Shield of Texas: Forms, Appeals, and PA Guide

Answer Box: Getting Enhertu Covered by Blue Cross Blue Shield of Texas

Eligibility: Patients with HER2-positive or HER2-low breast cancer, HER2-positive gastric cancer, or HER2-mutant NSCLC who meet FDA labeling criteria. Fastest path: Submit prior authorization with complete HER2 testing, medical necessity letter, and ILD monitoring plan through BCBS Texas provider portal. Start today: Contact your oncologist's office to request complete pathology reports and begin PA documentation. Appeals available through Texas Department of Insurance if denied.

Table of Contents

  1. Who Should Use This Checklist
  2. Member & Plan Basics
  3. Clinical Criteria Requirements
  4. Coding and Billing Information
  5. Documentation Packet Essentials
  6. Submission Process
  7. Specialty Pharmacy Requirements
  8. After Submission: What to Expect
  9. Common Denial Prevention Tips
  10. Appeals Process in Texas
  11. Printable Requirements Checklist

Who Should Use This Checklist

This guide is designed for patients and their healthcare teams seeking coverage for Enhertu (fam-trastuzumab deruxtecan-nxki) through Blue Cross Blue Shield of Texas. Use this checklist if you have:

  • HER2-positive or HER2-low breast cancer requiring targeted therapy
  • HER2-positive gastric or gastroesophageal junction adenocarcinoma
  • HER2-mutant non-small cell lung cancer (NSCLC)
  • A prescription from an oncologist for Enhertu treatment

Expected outcome: Following this comprehensive checklist significantly improves your chances of initial approval and reduces delays in treatment access.

Member & Plan Basics

Verify Active Coverage

Before starting the prior authorization process:

  • ✅ Confirm active BCBS Texas membership through your member portal
  • ✅ Check your plan type (commercial, employer-sponsored, or individual market)
  • ✅ Review specialty drug benefits in your Summary of Benefits and Coverage
  • ✅ Note your deductible status and out-of-pocket maximum

Authorization Requirements

Blue Cross Blue Shield of Texas requires prior authorization for specialty oncology medications like Enhertu. The drug is typically classified as a specialty medication requiring:

  • Prior authorization approval before dispensing
  • Use of preferred specialty pharmacy network
  • Medical necessity documentation
  • Ongoing utilization management

Clinical Criteria Requirements

FDA-Approved Indications

Enhertu must be prescribed for an FDA-approved indication:

HER2-Positive Breast Cancer

  • Unresectable or metastatic disease
  • Prior anti-HER2 therapy in the metastatic setting

HER2-Low Breast Cancer

  • Unresectable or metastatic disease
  • Prior chemotherapy in the metastatic setting

HER2-Positive Gastric Cancer

  • Locally advanced or metastatic disease
  • Prior trastuzumab-based therapy

HER2-Mutant NSCLC

  • Unresectable or metastatic disease
  • Prior systemic therapy

Required Biomarker Testing

Complete HER2 testing documentation is essential:

  • ✅ Immunohistochemistry (IHC) results with specific scores
  • ✅ In situ hybridization (ISH) results if applicable
  • ✅ ASCO/CAP interpretation of HER2 status
  • ✅ Pathology report from CLIA-certified laboratory
Note: HER2-low is defined as IHC 1+ or IHC 2+/ISH-negative. HER2-positive requires IHC 3+ or IHC 2+/ISH-positive.

Line of Therapy Documentation

Document previous treatments and outcomes:

  • ✅ Prior anti-HER2 therapies (trastuzumab, pertuzumab, T-DM1)
  • ✅ Reason for discontinuation (progression, toxicity, intolerance)
  • ✅ Duration of prior treatments and response
  • ✅ Performance status and ability to tolerate therapy

Coding and Billing Information

HCPCS J-Code

Enhertu is billed using HCPCS code J9358 with the following specifications:

  • Code: J9358 (Injection, fam-trastuzumab deruxtecan-nxki, 1 mg)
  • Billing unit: 1 mg = 1 billable unit
  • Medicare rate: Approximately $29.48 per mg (2025)

ICD-10 Diagnosis Codes

Breast Cancer Examples:

  • C50.011-C50.019: Malignant neoplasm of nipple and areola
  • C50.111-C50.119: Malignant neoplasm of central portion of breast
  • C50.211-C50.219: Malignant neoplasm of upper-inner quadrant

Gastric Cancer:

  • C16.0-C16.9: Malignant neoplasm of stomach
  • C16.0: Malignant neoplasm of cardia

NSCLC:

  • C78.00-C78.02: Secondary malignant neoplasm of lung
  • C34.10-C34.12: Malignant neoplasm of upper lobe, bronchus or lung

Required Modifiers

  • JW: Drug amount discarded/not administered to patient
  • JZ: Zero drug amount discarded/not administered to patient

Documentation Packet Essentials

Medical Necessity Letter Components

Your oncologist should include these elements in the medical necessity letter:

  1. Patient demographics and insurance information
  2. Primary diagnosis with ICD-10 code and staging
  3. HER2 testing results with interpretation
  4. Prior treatment history and outcomes
  5. Clinical rationale for Enhertu selection
  6. Dosing plan and administration schedule
  7. Monitoring plan for interstitial lung disease (ILD)
Clinician Corner: The medical necessity letter should specifically address ILD risk mitigation, as this is a key safety concern for payers. Include baseline pulmonary function tests and your monitoring schedule.

Required Attachments

  • ✅ Complete pathology report with HER2 testing
  • ✅ Treatment history with dates and outcomes
  • ✅ Baseline imaging (chest CT for ILD screening)
  • ✅ Performance status assessment
  • ✅ Laboratory results (CBC, comprehensive metabolic panel)
  • ✅ Cardiac function assessment if indicated

Submission Process

Correct Forms and Portals

Submit your prior authorization through:

  • Provider portal: BCBS Texas provider website (primary method)
  • Phone: Provider services line for urgent cases
  • Fax: Backup submission method (verify current fax number with BCBS Texas)

Common Rejection Fields

Avoid these frequent submission errors:

  • ✅ Complete member ID and group number
  • ✅ Correct prescriber NPI and DEA number
  • ✅ Accurate drug name and strength
  • ✅ Specific ICD-10 codes (not just category codes)
  • ✅ Legible signatures on all forms

Specialty Pharmacy Requirements

Preferred Network Vendors

BCBS Texas contracts with specific specialty pharmacies for oncology medications:

Preferred Vendors in Texas:

  • CHRISTUS Specialty Pharmacy: (903) 606-6790
  • Accredo: (833) 721-1619 (for self-administered specialty medications)

Transfer Process

  1. Prior authorization approval must be obtained first
  2. Prescription transfer to preferred specialty pharmacy
  3. Insurance verification by specialty pharmacy
  4. Delivery coordination to provider office or patient home

After Submission: What to Expect

Timeline and Status Checks

  • Initial review: 3-5 business days for complete submissions
  • Determination: Up to 15 business days for standard review
  • Expedited review: 72 hours for urgent clinical situations

Confirmation Documentation

Record these details after submission:

  • ✅ Prior authorization number or reference ID
  • ✅ Submission date and method
  • ✅ Expected decision date
  • ✅ Contact information for status updates

Common Denial Prevention Tips

Five Critical Pitfalls to Avoid

Pitfall Prevention Strategy Documentation Fix
Incomplete HER2 testing Submit complete pathology report with IHC/ISH scores Include ASCO/CAP interpretation
Missing ILD monitoring plan Document baseline pulmonary assessment Include chest imaging and monitoring schedule
Incorrect line of therapy Verify FDA labeling requirements Document prior therapies with dates and outcomes
Wrong specialty pharmacy Use BCBS Texas preferred vendors Transfer prescription after PA approval
Insufficient medical necessity Provide detailed clinical rationale Include guideline references and contraindications to alternatives

Appeals Process in Texas

Internal Appeals Timeline

If your initial prior authorization is denied:

  • Filing deadline: 180 days from denial notice
  • Decision timeframe: 30 days for pre-service appeals
  • Expedited appeals: 72 hours for urgent cases

Contact Information:

  • Phone: 1-888-657-6061 (TTY: 711)
  • Mail: BCBS TX Complaints and Appeals Department, P.O. Box 660717, Dallas, TX 75266-0717
  • Fax: 1-855-235-1055

External Review (Independent Review Organization)

Texas law provides access to independent external review through an IRO:

  • Eligibility: After internal appeal denial
  • Filing deadline: 4 months from final internal denial
  • Decision timeframe: 20 days (5 days for urgent cases)
  • Cost: Free to patients (insurer pays IRO fees)
Texas Advantage: The IRO's decision is binding on BCBS Texas, providing patients with a final avenue for coverage disputes.

When to Escalate

Contact the Texas Department of Insurance if:

  • BCBS Texas misses appeal deadlines
  • You need assistance with the appeals process
  • You believe your rights have been violated

Texas Department of Insurance: 1-800-252-3439

Printable Requirements Checklist

Before You Start

  • Active BCBS Texas membership verified
  • Specialty drug benefits confirmed
  • Oncologist consultation completed
  • FDA indication confirmed

Clinical Documentation

  • Complete HER2 testing results
  • Prior treatment history documented
  • Medical necessity letter completed
  • ILD monitoring plan included
  • Baseline assessments completed

Submission Requirements

  • Correct prior authorization form
  • All required attachments included
  • Preferred specialty pharmacy identified
  • Submission method confirmed

After Submission

  • Confirmation number recorded
  • Expected decision date noted
  • Status check schedule established
  • Appeal timeline understood

Counterforce Health helps patients, clinicians, and specialty pharmacies navigate complex insurance approvals by turning denials into targeted, evidence-backed appeals. Our platform analyzes denial letters, identifies specific rejection reasons, and drafts comprehensive rebuttals aligned with each payer's requirements—saving time and improving approval rates for critical medications like Enhertu.

FAQ: Common Questions About Enhertu Coverage

Q: How long does BCBS Texas prior authorization take for Enhertu? A: Standard review takes up to 15 business days. Expedited review for urgent cases is completed within 72 hours.

Q: What if Enhertu is non-formulary on my plan? A: You can request a formulary exception with medical necessity documentation showing why covered alternatives are inappropriate.

Q: Can I request an expedited appeal in Texas? A: Yes, if waiting for standard review would seriously jeopardize your health. Expedited appeals must be decided within 72 hours.

Q: Does step therapy apply if I've tried treatments outside Texas? A: Yes, prior treatments from any provider can count toward step therapy requirements if properly documented.

Q: What happens if my appeal is denied? A: You can request external review through an Independent Review Organization (IRO) within 4 months of the final internal denial.

Disclaimer: This information is for educational purposes only and does not constitute medical or legal advice. Coverage policies vary by plan and individual circumstances. Always consult with your healthcare provider and insurance company for specific coverage determinations. For additional assistance with insurance appeals in Texas, contact the Texas Department of Insurance at 1-800-252-3439 or visit their consumer help page.

Need help navigating a complex Enhertu denial? Counterforce Health specializes in turning insurance denials into successful appeals through evidence-based advocacy and payer-specific expertise.

Powered by Counterforce Health—AI that turns drug denials into evidence-based appeals patients and clinicians can submit today.