HCPCS code J1670 – Tetanus immune globulin injection

Key takeaways

J1670 covers the drug supply of tetanus immune globulin (human) at up to 250 IU per billed unit, not the injection service.

Units billed equal total IU administered divided by 250, rounded up to the next whole unit, so a 300 IU dose bills as 2 units.

Medicaid and many commercial payers require the NDC on the CMS-1500 or 837P, while Medicare Part B generally does not, so check your MAC.

Pabau’s claims management software captures dose, route and clinical documentation at the point of care, so J1670 claims start from a complete record.

HCPCS code J1670: Official descriptor and code attributes

HCPCS code J1670 is the Level II code for injectable tetanus immune globulin (TIG), maintained by the Centers for Medicare and Medicaid Services (CMS). The official descriptor reads: Injection, tetanus immune globulin, human, up to 250 units. It reports the drug supply in outpatient and physician office settings, one unit per 250 IU or part of it.

The drug is a pooled human plasma-derived passive immunization agent. In the United States it is sold as HyperTET (Grifols).

J-codes are reviewed every year and revised quarterly, so confirm the code’s active status against the CMS HCPCS Alpha-Numeric file each plan year. The table below summarizes the key attributes of HCPCS code J1670 as of the current CMS HCPCS release.

What J1670 covers and what it excludes

J1670 covers the drug cost of tetanus immune globulin only. It does not cover the injection service, any active tetanus vaccine, or wound debridement performed during the same encounter.

The distinction matters because coders occasionally apply J1670 when the patient received a tetanus toxoid vaccine (Td or Tdap) rather than passive immunization with TIG. These are different products with different codes.

• Included: Drug supply of tetanus immune globulin (human) administered IM for post-exposure prophylaxis or wound management.
• Excluded, active tetanus vaccines: CPT 90714 (Td, preservative-free, adult) and CPT 90715 (Tdap). These are vaccine product codes, and administration is billed with 90471/90472.
• Excluded, administration service: The injection service is coded separately with a companion CPT code (see below). J1670 is drug-only.
• Excluded, IV infusion: TIG is given IM, not IV. CPT 96365 (IV infusion, therapeutic) does not apply.
• Excluded, other immune globulins: Intravenous immune globulin (IVIG) and subcutaneous immune globulin are reported under separate J-codes, such as J1569 (Gammagard Liquid) and J1459 (Privigen). J1670 is tetanus-specific.

How to calculate and report units for HCPCS code J1670

J1670 is billed in units of up to 250 IU. Divide the total dose administered by 250 and round up to the next whole unit. Because the descriptor says “up to 250 units”, any partial increment bills as a full unit.

The chart below shows why a 300 IU dose and a 500 IU dose land on the same claim line.

Beyond the unit count, many payers want the NDC for the specific vial dispensed on the claim. On CMS-1500 paper claims, the NDC goes in the shaded area of box 24 with qualifier N4. On 837P electronic claims, it is reported in the LIN segment with the unit of measure qualifier (UN for units) and the quantity dispensed.

NDC reporting is mandated for Medicaid drug claims under the Deficit Reduction Act, and many commercial payers require it by policy. Medicare Part B does not generally require an NDC on professional claims. Confirm with your Medicare Administrative Contractor (MAC), since some MACs publish supplemental drug billing instructions.

J1670 vs CPT 90389: Which code each payer accepts

CPT 90389 is the CPT product code for tetanus immune globulin (human) for intramuscular use. J1670 is the HCPCS Level II code for the same drug. Both codes are active, so the choice depends on the payer.

Medicare uses J1670 for the TIG drug supply. Commercial and Medicaid plans differ, and some accept 90389 while others want J1670. Bill one code per dose, choosing the one the payer’s policy names.

If your charge description master (CDM) maps TIG to only one of the two codes, add payer-specific mapping. Medicare claims then carry J1670, and each commercial plan gets the code its policy names.

Which administration code to bill alongside J1670

J1670 covers the drug only. In most outpatient and office settings, the injection service is billed separately with 96372. The correct companion depends on the clinical setting and the route of administration.

Some payers bundle the administration code with the drug J-code and deny 96372 as inclusive. Check your payer’s bundling edits before assuming separate reimbursement. When 96372 is denied as bundled, J1670 still pays at its allowed amount.

Medicare and Medicaid reimbursement for HCPCS code J1670

Under Medicare Part B, J-code drugs are generally paid at Average Sales Price (ASP) plus 6%, before sequestration. When ASP data are unavailable, Wholesale Acquisition Cost (WAC) plus 3% applies instead. Current payment limits are published in the CMS quarterly ASP drug pricing files.

TIG is not classified as a preventive immunization benefit under Medicare Part B. Coverage depends on medical necessity documentation showing post-exposure prophylaxis is clinically indicated. That typically means a wound with an uncertain or incomplete tetanus vaccination history, per CDC Advisory Committee on Immunization Practices (ACIP) guidance.

For Medicaid, reimbursement rates and coverage rules vary by state. Fee-for-service Medicaid programs set their own drug payment methodologies, and managed care plans within each state may layer on extra requirements. Check the state Medicaid fee schedule before submitting a J1670 claim, and confirm whether the plan requires prior authorization (see below).

Prior authorization requirements for J1670

Medicare Part B does not generally require prior authorization (PA) for J1670. The drug is given in response to an acute wound exposure, which makes a prospective authorization process clinically impractical in most cases. Still, confirm with the relevant MAC, as requirements can change through coverage determination updates.

Commercial insurers and many state Medicaid plans are a different story. Some plans require PA or concurrent notification even for emergency-adjacent services. Insurance eligibility verification at the time of service should include a check for active PA requirements on J-code drugs under the patient’s plan.

When PA is required, the documentation typically requested includes:

• Wound description, mechanism of injury, and date of exposure
• Patient’s tetanus vaccination history (or documented inability to verify it)
• Clinical indication per ACIP wound-management guidelines
• Administering provider credentials and specialty
• Place of service and clinical setting

Documentation requirements for J1670 claims

Incomplete documentation sits behind many J1670 denials. A clean J1670 claim needs the elements below in both the clinical record and on the claim form before submission. Digital clinical forms that capture these fields at the point of care stop missing details from surfacing only at the billing stage.

• NDC number: Reported on the CMS-1500 or 837P with qualifier N4 wherever the payer requires it. The NDC must match the vial dispensed.
• Units billed: Total IU administered divided by 250, rounded up to the next whole unit.
• Route of administration: Documented as intramuscular (IM) in the clinical note.
• Clinical indication: Wound type, mechanism of injury, and immunization history documented to establish medical necessity.
• Administering provider credentials: The rendering provider’s NPI must appear on the claim. Their credentials must support the authority to administer injectable biologics.
• Place of service: The POS code must match the service location.
• Date of service: Must match the administration date in the clinical record.

For practices handling medical billing in-house, a J1670 claim checklist built into the documentation workflow catches the most common submission errors early. A superbill that pre-populates the code, units field and NDC prompt cuts manual entry for clinical staff.

Common reasons J1670 claims are denied and how to fix them

J1670 denials follow predictable patterns. The table below covers the most frequent denial reasons, the matching adjustment or remark code, and the corrective action for each.

Systematic denial management in healthcare for J-code drug claims means tracking denial codes by payer, not just by code. A pattern that shows up on Medicare claims may not appear on commercial claims, and vice versa. Payer-specific billing rules in your practice management system stop the same denial from recurring on resubmission.

Neighboring and easily confused codes

Several codes sit close to J1670 in the HCPCS code set and in CPT, and they cause consistent coder confusion. The quick-reference table below matches each scenario to the right code.

Submitting J1670 claims accurately with Pabau

Practices billing J1670 often record the dose in the clinical note and rebuild it later on the claim. When the units, route or NDC are keyed in again at the billing stage, a mismatch with the note drives the denial patterns above.

Pabau’s claims management software keeps the clinical record and the claim in one system. Clinicians capture the dose, route and clinical indication in documentation fields at the point of care. Billing staff then build the J1670 claim line from that record, rather than chasing details after the visit.

For practices aiming for clean claim submission on drug codes, one platform removes the hand-off errors between clinical and billing teams.

Streamline your J-code drug billing with Pabau

Pabau captures dose, route and clinical documentation at the point of care, so your billing team builds J1670 claims from a complete record. See how it works for your team.

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Conclusion

J1670 claims get paid when they are built from the dose record, not reconstructed at billing. Set your unit rule to round up, and map TIG to J1670 for Medicare and to each commercial payer’s preferred code.

Then confirm each payer’s NDC rule before the first claim goes out. Doing this once at setup costs far less than correcting CO-4 and CO-16 denials one remittance at a time.

Book a demo to see how Pabau keeps dose, route and wound documentation in the record your billing team works from.

Continue your research

Need a guide to common billing denial codes? Denial codes in medical billing covers the most frequent CARC and RARC codes and how to appeal them effectively.

Billing the TIG injection itself? CPT code 96372 explains when the injection service pays separately and which modifiers apply.

Giving Tdap at the same visit? CPT code 90715 covers the Tdap vaccine product code and how to bill it alongside TIG.

Want to understand how clearinghouses process J-code claims? Medical claims clearinghouse explains how electronic drug claims move from practice to payer and where errors are caught.

Looking for a practical overview of the 837P claim format? 837 file billing guide walks through the electronic claim structure used to submit HCPCS drug codes, including NDC segments.

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