HCPCS code J1620 – Gonadorelin hydrochloride injection

Key takeaways

HCPCS code J1620 (injection, gonadorelin hydrochloride, per 100 mcg) was deleted effective December 31, 2025, and is not billable for 2026 dates of service.

CMS has named no replacement code. For 2026 services, follow the CMS unclassified-drug route (J3490 with the NDC) and the payer’s own policy.

For dates of service on or before December 31, 2025, J1620 bills one unit per 100 mcg, with the NDC reported under qualifier N4.

Pabau, our practice management platform, validates claims before submission and tracks each one from pending to paid, so denials surface early.

What is HCPCS code J1620?

HCPCS code J1620 is the deleted Level II code for an injection of gonadorelin hydrochloride, per 100 micrograms. CMS deleted it effective December 31, 2025, so it is not billable for 2026 dates of service.

The official descriptor is: Injection, gonadorelin hydrochloride, per 100 mcg. J1620 entered HCPCS on January 1, 1982, and covered a drug that cannot be self-administered. That placed it under Medicare Part B rather than Part D. The Centers for Medicare and Medicaid Services (CMS) HCPCS program maintains the J-series codes.

J1620 sat in the J-code range for drugs given other than by mouth. Other codes in that range have their own pages in our HCPCS reference for coders.

Is J1620 still active? Code status and the 2026 deletion

No, J1620 is not active. The CMS October 2026 alpha-numeric HCPCS file lists it with action code D (deleted) and a termination date of December 31, 2025. The deletion took effect on January 1, 2026.

AAPC and Find-A-Code show the same deletion. Your Medicare Administrative Contractor (MAC) rejects J1620 on a 2026 date of service with an “invalid code for date of service” edit. Commercial payers that follow the CMS HCPCS master file reject it the same way.

The date of service decides which rule applies, not the date you submit the claim. A late claim for a December 2025 injection still bills J1620. A January 2026 injection does not, and the diagram below shows where each one goes.

What to bill instead of J1620 for 2026 dates of service

CMS has not named a replacement code for J1620, and no source we checked names one. Do not bill a code someone suggests in a forum without checking it against the payer.

For drugs with no specific HCPCS code, CMS guidance points to the unclassified-drug route. The Medicare Claims Processing Manual, Chapter 17 covers billing an unclassified drug under J3490 with the NDC. CMS does not designate J3490 as the official successor to J1620, so treat it as a route to confirm rather than a crosswalk.

1. Confirm the deletion in the current file. Download the latest alpha-numeric file from the CMS HCPCS program page and search for J1620.
2. Check the payer’s own policy. Medicare MACs, Medicaid plans and commercial payers each publish how they want unclassified drugs billed.
3. If the payer accepts the unclassified route, report J3490 with the 11-digit NDC, the drug name, the dose and the route in the claim narrative.
4. Keep the invoice and dose record on file. Payers often price unclassified drugs manually and may ask for them.
5. Update the charge master so 2026 gonadorelin charges no longer default to J1620.

Clinical overview: Gonadorelin hydrochloride

Gonadorelin hydrochloride is a synthetic form of gonadotropin-releasing hormone (GnRH), also called luteinizing hormone-releasing hormone (LHRH). It stimulates the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

Its documented clinical uses include:

• Evaluation of hypothalamic-pituitary function in diagnosing hypogonadotropic hypogonadism
• Delayed puberty assessment
• Female infertility, including ovulation induction when given in pulsatile infusion
• Diagnostic testing of pituitary LH reserve

Factrel, given subcutaneously or by IV, is the gonadorelin hydrochloride product that J1620 described. Lutrepulse was a separate gonadorelin acetate product given by pulsatile infusion pump, and J1620 did not describe it. Some formulations have been commercially discontinued, so confirm availability with the prescribing provider.

Fertility practices often document gonadorelin alongside ovulation-stimulating protocols in the treatment-cycle record. That record supports the diagnosis code on the claim.

Gonadorelin is a Part B drug because it is physician-administered by injection. Part D covers self-administered drugs only, so an injected drug billed to Part D is rejected at adjudication.

How J1620 was billed through 2025: Units, NDC and claim preparation

The steps below apply only to dates of service on or before December 31, 2025. Use them to work open claims, corrected claims and appeals. If your team is new to drug claims, start with how medical billing works for physician-administered injectables.

Step 1: Calculate billing units

J1620 is billed per 100 mcg administered. Divide the total dose given by 100 to get your unit count. Round up to the nearest whole unit if the dose is not a clean multiple of 100.

Step 2: Attach the NDC

Medicaid requires NDC reporting on physician-administered drug claims, and Medicare contractors often require it for unclassified drugs. A missing or invalid NDC is one of the most common denial triggers for drug J-codes. The NDC goes in the claim’s drug identification segment in this format:

• NDC qualifier: N4
• NDC format: 11-digit number in 5-4-2 configuration (for example, 12345-6789-01)
• Unit qualifier: UN (units), ML (milliliters) or GR (grams), depending on the package size descriptor
• NDC quantity: The quantity from the package administered, mapped to the package unit qualifier

Use the NDC from the vial or syringe administered, not a generic NDC. If several vials were opened to reach the dose, report the NDC of each vial used and record the lot numbers in the clinical record.

Step 3: Select the administration CPT code

The drug code and an administration CPT code must both appear on the same claim. Subcutaneous gonadorelin usually pairs with 96372, and the route decides the rest:

• CPT 96372: Therapeutic, prophylactic or diagnostic injection, subcutaneous or intramuscular (the most common pairing for subcutaneous gonadorelin)
• CPT 96374: IV push of a therapeutic drug (use if administered as an IV bolus)
• CPT 96365: IV infusion for therapy (use if administered as an IV infusion)

Step 4: Attach a supporting diagnosis code

Every drug claim needs a diagnosis code that establishes medical necessity. Codes used with gonadorelin include E23.0 (hypopituitarism, including hypogonadotropic hypogonadism), E30.0 (delayed puberty) and N97.0-N97.9 (female infertility by cause). The diagnosis must be documented in the clinical note for the date of service.

Medicare reimbursement for J1620 claims

CMS paid physician-administered Part B drugs under the Average Sales Price (ASP) method, generally at ASP plus 6%. ASP rates change quarterly, so the amount for a J1620 claim depends on the quarter of its date of service. This page does not quote a dollar rate for that reason.

For a 2025 or earlier date of service, check the CMS quarterly ASP pricing file for that quarter. Your MAC’s drug fee schedule carries the same rates. The CMS Physician Fee Schedule lookup tool also returns HCPCS status by year. The AAPC HCPCS code database and PGM Billing’s HCPCS lookup help with descriptor checks.

Hospital outpatient departments bill under the Outpatient Prospective Payment System (OPPS) and may be paid a different rate. Check with your MAC if your facility is not a standard outpatient department or physician office.

Prior authorization and medical necessity for gonadorelin

Traditional Medicare generally does not require prior authorization for Part B drug injections. Coverage still depends on medical necessity. The drug must match a covered diagnosis under any applicable National Coverage Determination (NCD) or Local Coverage Determination (LCD).

Commercial payers and Medicaid plans often require prior authorization (PA) where Medicare does not. Rules vary by payer and MAC jurisdiction, and they apply whether the claim uses J1620 or an unclassified code. Verify with each plan before the drug is given.

When prior authorization is granted, record the PA number in Box 23 of the CMS-1500 and in the patient’s chart. A claim submitted without an issued PA number denies on the “authorization required” edit.

Codes frequently confused with HCPCS code J1620

Gonadorelin is one drug in a larger class of GnRH-related drugs, and several of them have their own J-codes. The drug on the claim must match the drug in the clinical record and its approved indication for the billed diagnosis.

The most damaging mix-up is between J1620 and the leuprolide codes. Gonadorelin stimulates the pituitary, while leuprolide suppresses it with continuous use. J9217 and J9218 are billed for advanced prostate cancer, so a fertility workup patient should never carry either code.

Top denial reasons for J1620 claims and how to fix them

Good denial management in healthcare for drug J-codes starts with knowing which edits fire. The table below maps six common J1620 denial triggers to their fixes.

Documentation checklist for gonadorelin claims

A clean claim for a drug code starts with documentation that supports every field on the 837P or CMS-1500. Use this checklist for J1620 claims through 2025 and for unclassified-drug claims from 2026.

• Drug name and manufacturer: Gonadorelin hydrochloride with the brand and manufacturer on record
• Lot number: From the vial(s) administered, kept in the medication administration record
• NDC: 11-digit NDC from the administered vial in 5-4-2 format
• Dose in micrograms: The exact mcg administered, documented in the clinical or nursing note
• Units billed: Dose ÷ 100 mcg for J1620, or the unit the payer specifies for an unclassified code
• Route of administration: Subcutaneous, intramuscular or IV, matching the administration CPT selected
• Date of injection: Matching the date of service on the claim, which also decides whether J1620 is valid
• Administering provider: Name and NPI of the clinician who gave the injection
• Supporting ICD-10-CM diagnosis: A covered diagnosis (for example, E23.0, E30.0 or N97.x) documented in the clinical note
• Prior authorization number: If the payer requires one, recorded in the chart and on the claim

How Pabau helps practices bill gonadorelin after the J1620 deletion

A deleted J-code tends to surface as a run of denials weeks after January, once remittances come back. By then, billing staff are reworking claims instead of preventing them.

Pabau, the practice management platform we build, includes claims management software that validates each claim before it goes out. Claims are submitted electronically through clearinghouses on the CMS-1500, and each one is tracked from pending to paid. Electronic remittance advice (ERA) shows which claims came back denied and why.

Prior authorization codes are managed on the claim, so the number is on hand when a commercial payer asks for it. When a wave of “invalid code” denials lands, the pending-to-paid view makes the pattern visible within days.

Catch drug-code denials before they pile up

Pabau’s claims management validates claims before submission, sends them electronically through clearinghouses, and tracks each one from pending to paid. Your practice sees denials early and reworks fewer claims.

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Conclusion

J1620 is gone for 2026 dates of service, and no replacement code is coming to make the switch automatic. Retire the code in your charge master now, then confirm each payer’s route for unclassified drugs before the next gonadorelin injection.

Keep the J1620 billing rules on file rather than deleting them. Claims, corrections and appeals for 2025 services still need them, and the date of service decides which rule applies. Book a demo to see how Pabau helps your practice catch code-change denials before they reach your receivables.

Continue your research

Billing a 2026 gonadorelin injection? HCPCS code J3490 explains how unclassified drugs are billed with the NDC, dose and drug name.

Need a reference on IVF procedure codes? IVF CPT codes reference covers the CPT codes paired with reproductive endocrinology billing, including which codes pair with drug J-code submissions.

Billing a GnRH agonist instead? HCPCS code J1950 covers leuprolide acetate, the GnRH drug most often confused with gonadorelin on a claim.

Tracking down why claims keep getting denied? Denial management in healthcare walks through the denial workflow from CARC code identification through corrected-claim submission and appeal.

Frequently asked questions