Haegarda (C1 esterase inhibitor SC) — HCPCS J0599

HAE drug class comparison FDA labels verified May 2026

Five HAE-specific products with distinct HCPCS codes, routes, and indications. Get the right one before billing.

Hereditary angioedema (HAE) management splits into two clinical buckets: routine prophylaxis (prevent attacks) and on-demand / acute treatment (abort an attack in progress). Haegarda is a prophylaxis-only product. Picking the wrong HCPCS for the wrong indication is a top-five denial in HAE billing.

Haegarda SC vs. Cinryze IV — same molecule, different billing FDA verified May 2026

Two CSL Behring C1-INH prophylaxis products with overlapping active ingredients but completely different billing pathways.

Dosing & unit math FDA label verified May 2026

Weight-based fixed-frequency SC injection. Vial sizes are fixed, so partial-vial waste is common.

Standard dose

• 60 IU/kg SC every 3–4 days (typically twice weekly, every ~3.5 days — e.g., Monday/Thursday or Tuesday/Friday)
• For HAE Type I and Type II in adolescents (≥12 years) and adults
• Reconstitute lyophilized powder with sterile water for injection
• Final concentration after reconstitution: 500 IU/mL
• Inject SC into abdomen (preferred), upper arm, lateral thighs, or dorsal hips
• Approximately 104 doses per year (twice weekly × 52 weeks)

Unit math (10 IU = 1 unit)

Worked example — first-year billing for an 80 kg patient on routine prophylaxis

NDC & vial reference FDA NDC Directory verified May 2026

Verify NDCs at billing time against the FDA National Drug Code Directory and the CSL Behring product label. NDCs are CSL Behring-specific (labeler 63833).

Q2 2026 ASP status CMS ASP file checked May 2026

J0599 may not yet have a published ASP+6% payment limit. Verify the current quarterly file.

As of the Q2 2026 CMS Part B Drug ASP Pricing File review for this page, an ASP+6% payment limit for J0599 may not be published. This is common for products that are predominantly billed through specialty pharmacy benefit (not Part B medical benefit) — manufacturers report ASP primarily for products with significant Part B utilization.

Why ASP may be missing for J0599

• Most Haegarda is dispensed through specialty pharmacy benefit, not provider buy-and-bill
• Patient self-administration shifts billing away from Part B
• ASP submissions reflect only the Part B sales channel
• If your MAC requires invoice pricing in absence of ASP, document acquisition cost on the claim

Administration codes CPT verified May 2026

Subcutaneous injection — do NOT bill IV infusion codes.

Self-administration vs. clinic billing Verified May 2026

After patient training, billing pathway shifts from medical benefit to specialty pharmacy benefit.

Haegarda is explicitly designed for patient self-administration. The FDA label supports SC self-injection after appropriate training. Most maintenance dosing happens at home, with billing flowing through specialty pharmacy rather than provider buy-and-bill.

Modifiers CMS verified May 2026

JZ — whole-vial doses with no waste

Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. For Haegarda, JZ applies when the patient's calculated 60 IU/kg dose exactly matches a whole-vial combination (e.g., 50 kg patient = 3,000 IU = 1 × 3,000 IU vial; 100 kg patient = 6,000 IU = 2 × 3,000 IU vials).

JW — partial-vial waste (the common case)

Because vials are fixed at 2,000 IU and 3,000 IU and dosing is weight-based, partial-vial waste is the norm. Bill JW with the discarded units on a separate claim line. Example: 80 kg patient receives 4,800 IU using one 2,000 IU + one 3,000 IU vial; 200 IU discarded → bill 480 units J0599 (JZ on the admin line) + 20 units J0599 (JW on the waste line).

Modifier 25 — same-day E/M (training visit)

Use modifier 25 on the E/M code when a significant, separately identifiable evaluation and management service (e.g., self-admin training, dose adjustment, treatment-failure assessment) is performed on the same day as the injection.

340B modifiers (JG, TB)

For 340B-acquired Haegarda, follow your MAC's current 340B modifier policy. CSL Behring's billing guide does not provide 340B-specific instructions.

ICD-10-CM for HAE FY2026 verified May 2026

Document HAE Type I or Type II diagnosis. Pair complement-disorder code with clinical-manifestation code.

Site of care & place of service Verified May 2026

UnitedHealthcare and other major payers steer Haegarda toward home self-administration once the patient is trained. The economics favor specialty pharmacy + POS 12 (home) over recurring clinic visits.

Claim form field mapping CSL Behring guide May 2026

For clinic-administered Haegarda on CMS-1500 / 837P. Self-admin doses bill via NCPDP through specialty pharmacy.

Payer policy snapshot Reviewed May 2026

All major payers require PA with HAE Type I/II confirmation, attack frequency documentation, and specialist consultation.

Step therapy

Some payers require step therapy through Takhzyro (J0593, lanadelumab SC prophylaxis) or vice versa. Many plans treat Haegarda and Takhzyro as preferred alternatives at parity. Step therapy from on-demand therapy (Berinert, Ruconest, Firazyr, Kalbitor) to prophylaxis is typical — most policies require documentation of attack frequency ≥1/month or significant impact despite acute therapy before approving prophylaxis.

Medicare reimbursement CMS Q2 2026 (live-bound)

Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.

Coverage

No NCD specific to C1-INH SC. Coverage falls under MAC LCDs for biologics and HAE-specific local policies. All MACs cover J0599 for FDA on-label use (HAE Type I or Type II prophylaxis) with appropriate ICD-10 and documented attack frequency. Medicare Part D covers the dispensing pathway for self-admin maintenance in most plans.

Code history

• J0599 — HCPCS code "C-1 esterase inhibitor, haegarda, 10 units," Haegarda-specific
• Pre-permanent-code period: billed via unclassified J3490 with Haegarda NDC documentation
• FDA approval: June 2017 (BLA 125598); first SC C1-INH for HAE prophylaxis

Patient assistance — CSL Behring AssureSupport CSL Behring verified May 2026

• Haegarda Patient Support / CSL Behring AssureSupport: 1-855-999-3273 (Haegarda-specific) / 1-877-355-IGIV (CSL Behring AssureSupport general line)
• Haegarda Co-Pay Program: commercial copay assistance for eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients); $0 first dose for eligible commercial patients
• CSL Behring Patient Assistance Program: free product for uninsured / underinsured patients meeting income requirements (administered through CSL Behring Patient Assistance Program, Inc., a 501(c)(3))
• Foundations: for Medicare patients ineligible for manufacturer copay programs, refer to PAN Foundation HAE fund, HealthWell HAE fund, NORD HAE fund — verify open funds quarterly
• Travel & lodging: CSL Behring AssureSupport offers limited travel assistance for verified financial-hardship cases attending HAE-specialist appointments
• Web: haegarda.com / cslbehring.com

Common denials & how to fix them

Frequently asked questions

What is the HCPCS code for Haegarda?

Haegarda is billed under HCPCS J0599 — "Injection, C-1 esterase inhibitor (human), Haegarda, 10 units." One billable unit equals 10 IU of drug. A typical 60 IU/kg dose for an 80 kg patient (4,800 IU) is billed as 480 units of J0599. J0599 is specific to the subcutaneous Haegarda product and should NOT be used for the IV C1-INH products: Cinryze (J0598), Berinert (J0597), or Ruconest (J0596).

How many units do I bill for a Haegarda dose?

Bill the total IU administered divided by 10. For a weight-based 60 IU/kg dose: 70 kg patient = 4,200 IU = 420 units; 80 kg patient = 4,800 IU = 480 units; 100 kg patient = 6,000 IU = 600 units. Because Haegarda comes in fixed 2,000 IU and 3,000 IU vials, partial-vial waste is common — bill JW for the discarded portion alongside JZ-style admin lines for the units administered.

What administration CPT do I use for Haegarda?

CPT 96372 — "Therapeutic, prophylactic, or diagnostic injection, subcutaneous or intramuscular" — is the correct admin code for clinic-administered Haegarda. Do NOT bill IV infusion codes (96365/96366). Haegarda is a subcutaneous injection, distinct from the IV C1-INH products. After patient training, most Haegarda doses are self-administered at home and billed through specialty pharmacy benefit, not provider buy-and-bill.

Is Haegarda for HAE attacks or prophylaxis?

Haegarda is FDA-approved for routine prophylaxis only — to prevent HAE attacks in adolescents and adults with HAE Type I or Type II. It is NOT indicated for treatment of acute attacks. For acute attacks, use Berinert (IV C1-INH, J0597), Ruconest (recombinant C1-INH IV, J0596), Firazyr/icatibant SC, or Kalbitor/ecallantide SC. Submitting a J0599 claim with an acute-attack ICD-10 + on-demand documentation will trigger denial.

What is the Medicare reimbursement for J0599?

As of Q2 2026, J0599 may not have an established CMS Part B ASP+6% payment limit published in the quarterly ASP file. Until CMS publishes an ASP for J0599, MACs typically reimburse based on invoice cost or wholesale acquisition cost (WAC) less applicable percentage per local policy. Verify the current quarterly ASP file at billing time. Most Haegarda is billed through specialty pharmacy benefit (not Part B), so ASP applicability is limited.

How is Haegarda different from Cinryze?

Haegarda and Cinryze are the same molecule (plasma-derived human C1 esterase inhibitor) but different formulations. Haegarda is subcutaneous (J0599, FDA-approved 2017, 60 IU/kg SC every 3–4 days); Cinryze is intravenous (J0598, FDA-approved 2008, 1,000 IU IV every 3–4 days). Haegarda is preferred for patients who want to avoid IV access and self-administer at home. Both are CSL Behring products approved for HAE prophylaxis only. Cinryze admin uses IV codes (96365/96366); Haegarda uses SC code 96372 or self-admin via specialty pharmacy.

Can patients self-administer Haegarda?

Yes — patient self-administration after proper training is the norm for Haegarda and is explicitly supported by the FDA label. Initial training is typically conducted in clinic (bill 96372 + drug J0599 for that visit), but ongoing maintenance doses are self-administered at home. After self-admin transition, billing shifts from medical benefit (provider buy-and-bill) to specialty pharmacy benefit. Place of service 12 (home) is most common.

What ICD-10 codes are used for Haegarda?

Primary ICD-10 codes: D84.1 (defects in complement system) is the most commonly used and most payers' preferred primary diagnosis for HAE C1-INH deficiency. D89.49 (other complement disorder) is used for some HAE variants. T78.3xxx (angioneurotic edema) describes the clinical manifestation but should be paired with the underlying complement-disorder code, not used alone. HAE Type I (low antigenic + functional C1-INH) and HAE Type II (normal antigenic, low functional) are both covered. Haegarda is NOT approved for HAE with normal C1-INH (Type III / HAE-nC1INH).

Source documents

1. Haegarda — HCP product information & coding resources (CSL Behring)
   Product website with HCP coding & coverage documents
2. DailyMed — HAEGARDA (C1 esterase inhibitor subcutaneous, human) Prescribing Information
   FDA-approved label, BLA 125598
3. FDA Drugs@FDA — Haegarda BLA 125598 approval documents (June 2017)
4. CMS — Medicare Part B Drug ASP Pricing File
   Q2 2026 quarterly file (verify J0599 listing at billing time)
5. CMS — HCPCS Level II quarterly file (J0599 descriptor)
6. US Hereditary Angioedema Association (US HAEA) — HAE management guidelines
7. WAO/EAACI 2021 HAE Guideline Update — international management consensus
8. UnitedHealthcare — Medical Drug Policies (HAE / C1-INH coverage)
9. Aetna Clinical Policy Bulletins — HAE / C1-INH
10. CSL Behring — AssureSupport patient services portal
11. FDA National Drug Code Directory

About this page

We maintain this page as a living reference. Medicare ASP pricing is bound to our underlying CareCost data layer and refreshes automatically when CMS publishes new quarterly files. Coding and policy content is reviewed at least quarterly and updated whenever a source document changes.

Found an error? Email hello@carecostestimate.com.

Refresh cadence

Reviewer

Change log

• May 2, 2026 — Initial publication. ASP data: Q2 2026 (pending CMS publication for J0599). Manufacturer source: CSL Behring HCP coding resources 2026. FDA label: most recent revision (BLA 125598). Cross-references to Cinryze (J0598), Berinert (J0597), Ruconest (J0596), Takhzyro (J0593).

Methodology

Every claim on this page is sourced inline. Pricing reflects the current CMS Part B Drug ASP Pricing File (handles "ASP pending" status gracefully via live binding). Payer policies are read directly from each payer's published medical/pharmacy policy documents. Indication and dosing are verified against the current FDA label. We do not paraphrase from billing-software vendor blogs.