HCPCS code J3358 – Ustekinumab intravenous injection

Key takeaways

HCPCS code J3358 is ustekinumab for intravenous injection, billed per 1 mg, while J3357 is the subcutaneous code.

J3358 covers the single weight-based IV induction dose for Crohn’s disease and ulcerative colitis: 260, 390 or 520 mg.

Bill one unit per milligram, so the three doses are 260, 390 or 520 units, and 520 is also the Medicare MUE.

Each dose uses whole 130 mg vials, so the claim line normally carries the JZ modifier for zero waste.

Biosimilar ustekinumab products bill under their own Q-codes, never J3358, and the Medicare rate differs for each one.

HCPCS code J3358 bills IV ustekinumab by the milligram

HCPCS code J3358 describes “ustekinumab, for intravenous injection, 1 mg.” It covers the one-time IV induction infusion of ustekinumab in Crohn’s disease and ulcerative colitis. The maintenance doses that follow go under the skin and bill as J3357.

Ustekinumab is a monoclonal antibody that blocks interleukin-12 and interleukin-23 by binding the p40 subunit the two cytokines share. Janssen Biotech markets it as Stelara. J3358 took effect on January 1, 2018, according to the CMS HCPCS quarterly update files.

The split by route started a year earlier. A CGS Medicare coding notice confirmed that from January 1, 2017, J3357 covered only subcutaneous ustekinumab. J3358 now sits among the HCPCS Level II J-codes for drugs given other than by mouth, listed in our HCPCS library for billers.

Report the 11-digit NDC of the vial you infused alongside J3358. CMS’s October 2026 NDC-HCPCS crosswalk maps both Janssen vials above to J3358, each at 130 billing units per vial. Pull the NDC from the carton in hand rather than from a saved list.

Only Crohn’s disease and ulcerative colitis support J3358

IV ustekinumab is labeled for induction in moderately to severely active Crohn’s disease and ulcerative colitis, so those are the diagnoses that support J3358. Psoriasis and psoriatic arthritis are treated with subcutaneous doses only, which bill under J3357.

Code to the highest specificity the chart supports. If the note documents a complication such as rectal bleeding or an abscess, report the matching K50 or K51 complication code instead.

Body weight on the day sets the J3358 units

Bill one unit for every milligram infused. The induction dose depends on the patient’s body weight on the day of the infusion, and each band uses whole 130 mg vials.

Dose and units by weight band

The chart follows each band through to the claim line, using a 72 kg patient as the worked example.

Two errors account for most unit problems. Some billers enter the number of vials, so a 390 mg dose goes out as 3 units instead of 390. Others bill a dose that doesn’t match the documented weight band, which a payer reviewing the chart will reject.

The CMS medically unlikely edit for J3358 is 520 units per date of service, matching the top weight band. Units above 520 on one date of service are denied, and no labeled dose exceeds it.

Whole vials make JZ the normal J3358 modifier

J3358 is on the CMS list of single-dose container drugs subject to the JW and JZ modifier policy. Separately paid Medicare Part B claims must carry one or the other on every J3358 line.

• JZ: Append it when no drug was discarded. Because every induction dose uses whole vials, this is the normal case for J3358.
• JW: Report it on a separate line for the milligrams discarded from an opened vial, with the amount documented in the record.
• Never both on one line: A line carries JZ or JW, not the two together.

A JW line on a J3358 claim deserves a second look. With doses built from whole vials, discarded drug usually means the dose or the weight band was recorded wrongly.

The route decides between J3358 and J3357

Choose by route. J3358 is the IV infusion given once at the start of treatment for Crohn’s disease or ulcerative colitis. J3357 covers every subcutaneous dose, including IBD maintenance and the psoriasis and psoriatic arthritis doses.

The first subcutaneous dose, 90 mg, is due eight weeks after the IV infusion. Check that the authorization covers both routes before that visit, since some plans approve the IV induction and the maintenance doses separately.

Bill the infusion with 96413 and match the place of service

Bill the infusion with CPT 96413 for the first hour. Stelara IV is diluted in 250 mL of 0.9% sodium chloride and infused over at least one hour, so 96413 usually stands alone.

• 96413: Chemotherapy and complex drug or biologic administration, IV infusion, up to one hour. Medicare’s Claims Processing Manual includes monoclonal antibodies in the scope of these codes.
• 96415: Each additional hour, reported only when the infusion runs more than 30 minutes past the first hour.
• Start and stop times: Document both in the infusion record, because they decide whether 96415 applies.

Some commercial payers expect 96365 for biologic infusions instead. Check the payer’s drug administration policy before you bill the first induction.

Biosimilars never go on a J3358 line

An ustekinumab biosimilar is never billed with J3358. Each biosimilar has its own Q-code, and you report the code for the product you infused. The table lists the codes and Medicare payment limits in CMS’s October 2026 ASP files.

Wezlana and Pyzchiva have separate IV codes, while the other five biosimilars share one code across the vial and the syringes. For a shared code, the NDC on the claim tells the payer which form you infused. Several biosimilar limits include the temporary add-on of 8% of the reference product’s ASP.

Medicare pays J3358 at ASP plus 6%, and Medicaid varies

Medicare Part B pays J3358 at ASP plus 6%, set per milligram and updated each quarter. The October to December 2026 payment limit is $10.249 per unit, based on second-quarter 2026 sales data. Recheck it whenever CMS posts a new quarter’s file.

At that rate, the drug portion of a 390 mg induction is about $3,997 before adjustments. The patient owes 20% coinsurance, and the 2% Medicare sequestration cut reduces the amount paid to the practice.

Medicaid rates for J3358 vary by state, because each state agency sets its own physician-administered drug fee schedule. Check the state fee schedule each quarter, since it doesn’t move in step with Medicare’s ASP updates.

Most payers want prior authorization before the infusion

Most commercial plans, Medicare Advantage plans and Medicaid programs require prior authorization before an IV ustekinumab induction. Original Medicare has no national prior authorization requirement for J3358, but the claim must still meet your MAC’s coverage rules.

What the request needs

• Confirmed Crohn’s disease or ulcerative colitis diagnosis with the ICD-10-CM code and notes on disease activity
• Prior therapies tried and the response, to meet any step-therapy rule in the payer’s ustekinumab policy
• Ordering prescriber’s NPI and specialty
• Drug, dose, route and frequency, with the body weight that sets the 260, 390 or 520 mg dose
• The NDC of the product to be infused, which matters when the plan prefers a biosimilar
• Site of care, because some plans steer infusions away from hospital outpatient departments

Request authorization for the IV induction and the subcutaneous maintenance doses together where the payer allows it. Record the authorization number before the infusion date, so the claim is complete when it goes out. A sound claims management workflow keeps that number with the claim.

How long a decision takes

Since January 1, 2026, a CMS rule requires Medicare Advantage, Medicaid and CHIP plans to decide standard requests within 7 calendar days. Expedited requests must be decided within 72 hours. Employer-sponsored commercial plans aren’t bound by that rule, so build in extra lead time for them.

How a J3358 claim moves from infusion to payment

Take an illustrative patient: a 72 kg adult with moderately to severely active Crohn’s disease, starting ustekinumab. Here’s how the induction travels from booking to remittance.

1. Authorization first. The plan approves the IV induction and the maintenance doses. The number goes on file before the infusion is booked.
2. Weight on the day. The nurse weighs the patient at 72 kg, which puts the dose at 390 mg from three 130 mg vials.
3. The infusion. Start and stop times go in the record. The infusion runs about an hour, so 96413 stands alone.
4. The claim line. J3358 goes out with 390 units, JZ and the vial’s NDC. A K50 code at the highest documented specificity supports it, with POS 11 on the CMS-1500.
5. The remittance. Medicare’s drug portion comes to about $3,997 before coinsurance and sequestration. Any short payment gets worked from its CARC.

Eight weeks later, the first 90 mg subcutaneous dose bills as J3357. That second claim is where a wrong code most often slips in.

Check these seven items before you submit

Complete documentation at the time of the infusion prevents most J3358 denials. Good medical billing compliance treats this list as a pre-submission check rather than a retrospective audit.

• ICD-10-CM code: A Crohn’s disease or ulcerative colitis code at the highest specificity documented.
• Weight and dose: The weight recorded on the infusion date and the dose it sets, in milligrams.
• Product and NDC: The 11-digit NDC and lot number of each vial used.
• Route and times: IV route, dilution, and the infusion start and stop times.
• Waste: Zero waste for a JZ line, or the milligrams discarded for a JW line.
• Place of service: A POS code that matches where the infusion happened.
• Authorization: The prior authorization number and its approved dates.

Common J3358 mistakes and the denials they cause

J3358 denials follow predictable patterns. The Claim Adjustment Reason Code (CARC) and Remittance Advice Remark Code (RARC) on the remittance point you to the fix.

When the fix is an appeal, not a resubmit

For Original Medicare, the first appeal level is a redetermination by your Medicare Administrative Contractor (MAC). File it within 120 days of receiving the initial determination.

Include the infusion record, the weight used for dosing, the NDC and the authorization if there is one. Tracking each denial by CARC on receipt, as part of denial management, tells your team whether to correct and resubmit or appeal.

For commercial medical-necessity denials, a peer-to-peer review with the plan’s medical director is often the fastest route. Ask for it promptly, because many plans limit how long after the denial it can be held.

How Pabau keeps J3358 infusion claims complete

An IV ustekinumab claim passes through several hands. The infusion nurse records the dose, the front desk holds the authorization, and the biller retypes both into the claim. Each handoff is a chance for 390 units to go out as 3.

Pabau, the practice management and billing platform we build, tracks the authorization code, its dates and its sessions on the patient’s case. Your team gets a warning when the code is missing, so an unauthorized induction doesn’t reach the payer. Claims are created as CMS-1500 (837P) claims from that same case.

In the US, claims go out through Claim.MD, with eligibility checks before the infusion and secondary claims where a second payer applies. Remittances post back as ERAs, so you can see which J3358 claims were paid, short-paid or denied.

Send complete infusion claims the first time

Pabau tracks each authorization on the patient’s case, warns when one is missing and submits CMS-1500 claims through Claim.MD. ERA remittances post back, so your team sees each J3358 payment or denial.

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Conclusion

J3358 is a once-per-course code, and that is where its risk sits. A practice may bill it only a few times a year. That makes the weight band, the whole-vial units and the JZ modifier easy to forget.

Write the induction steps into your infusion checklist, from the weight check to the JZ modifier and the authorization number. Then confirm the product before the vial is opened, because a biosimilar switch changes the code.

Book a demo to see how Pabau carries those details from the patient record to a clean claim.

Continue your research

Need a broader overview of HCPCS billing fundamentals? Medical billing fundamentals explains how physician-administered drug claims flow from administration to reimbursement.

Seeing repeat denials across your biologic drug claims? Denial management in healthcare covers how to build a systematic tracking and appeal process.

Want to understand what a clean drug claim looks like before submission? What makes a clean claim walks through the fields payers check first on physician-administered drug submissions.

Submitting the authorization request yourself? Medical prior authorization form lays out the clinical and drug details payers ask for.

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