HCPCS code J3365: Urokinase IV injection, 250,000 IU vial

Key takeaways

HCPCS code J3365 described injection, intravenous, urokinase, 250,000 IU vial. It billed the drug cost separately under Medicare Part B.

CMS deleted J3365 effective December 31, 2025. The code is invalid for dates of service on or after January 1, 2026.

The deletion was routine annual maintenance. CMS deleted 101 long-unused codes in the 2026 HCPCS Level II update, including sibling code J3364.

The 1999 Abbokinase events are a separate story. FDA reapproved the product in 2002 and it stayed on the US market.

Claims with 2025 dates of service still belong on J3365 inside the timely filing window. Use J3490 for 2026 dates of service.

Practice management software like Pabau flags retired drug codes before submission and captures dose, route, and NDC at the point of care.

HCPCS code J3365 covered one intravenous injection of urokinase from a 250,000 IU vial. CMS deleted the code effective December 31, 2025, so it stopped being billable on January 1, 2026. Any claim carrying it for a 2026 date of service will be denied.

That timing changes how billers should treat the code. J3365 was valid for all of 2025, so open claims, resubmissions, and appeals with 2025 dates of service still belong on it. For a few more months, coders are working both sides of one cutover date.

Two things about J3365 are widely misreported. The deletion is often blamed on the 1999 Abbokinase warning letter, and the code is often described as long gone. Neither is right, and the sections below set out the documented timeline, the reimbursement history, and the cutover steps.

What is HCPCS code J3365?

HCPCS code J3365 was the Healthcare Common Procedure Coding System (HCPCS) Level II code for one intravenous dose of urokinase. One unit meant one 250,000 IU vial. The code sat in the J-series, which covers drugs given by injection or infusion that a patient cannot self-administer.

The table below summarizes the reference data for J3365 as it stood in the HCPCS Level II code set through 2025.

J3365 was maintained by the Centers for Medicare and Medicaid Services (CMS) through the annual HCPCS Level II update cycle. Like every J-code, it billed the drug cost itself. The administration CPT code, usually 96365 (or 96366 for additional hours), went on the same claim as a separate line.

Code status: Deleted effective December 31, 2025

J3365 is no longer billable. CMS deleted it effective December 31, 2025, which makes it invalid for dates of service from January 1, 2026 onward.

The code was not quietly dropped decades ago, which is a common misreading. Plenty of drug codes were deleted that long ago, including J0970 in 2011. J3365 stayed in the HCPCS Level II set right through 2025.

CMS did flag it “no maintenance” on January 1, 2018. That flag meant the agency stopped updating its descriptor and pricing data, while leaving the code in place.

What the deletion means in practice:

• Claims with a date of service on or after January 1, 2026 will be denied by Medicare and by commercial payers.
• Claims with a date of service on or before December 31, 2025 still use J3365. File them inside the payer’s timely filing limit.
• Denials on 2026 claims typically return denial code CO-4, inconsistent with covered service, or a code-invalid edit from the payer’s front-end scrub.
• Charge masters, superbills, and claim templates built before 2026 still carry J3365. Those need clearing now, not eventually.
• State Medicaid programs followed CMS. The Texas Medicaid bulletin and Colorado’s HCPF bulletin both list J3364 and J3365 as discontinued effective December 31, 2025.

Leaving a deleted code in an active charge description master (CDM) is a compliance risk during OIG or MAC audits. The deletion is recent enough that old entries often survive in charge masters and superbills.

What drug does J3365 represent?

Urokinase is a thrombolytic enzyme, specifically a direct plasminogen activator. It converts plasminogen to plasmin, which then breaks down fibrin clots. Unlike tissue plasminogen activator (tPA) drugs, urokinase acts on both fibrin-bound and circulating plasminogen.

Clinicians used urokinase mainly for the indications below, which is why it earned a dedicated HCPCS drug code:

• Pulmonary embolism (PE): IV urokinase was used to dissolve acute massive PE when systemic thrombolysis was indicated.
• Deep vein thrombosis (DVT): Given to restore venous patency in selected DVT cases.
• Occluded IV catheters: A lower-dose formulation, Abbokinase Open-Cath, restored patency in occluded central venous access devices. That product had its own code, J3364.

Urokinase was a high-cost, physician-administered drug given only in inpatient or hospital outpatient settings. That profile qualified it for separate payment under the Medicare Part B drug benefit. J-codes exist to capture separately reimbursable drug costs like this one.

Practices running IV therapy services should keep clear records of which drugs were given under which code, and when. Consistent IV therapy documentation makes a later audit far less painful.

Why J3365 was deleted in the 2026 HCPCS update

The deletion was routine housekeeping in the annual code-set cleanup. The January 2026 HCPCS Level II update added 160 new codes and deleted 101, J3365 among them. Every deleted code had gone long unused.

J3365 had carried a “no maintenance” flag since January 1, 2018. That flag tells payers the code still exists, but CMS has stopped maintaining its descriptor and payment data. Codes often sit in that state for years before CMS finally clears them out in a batch.

The 2026 batch is documented in CMS Transmittal R13575CP and in Integrated OCE version 27.0. Sibling code J3364, injection, urokinase, 5,000 IU vial, was retired on the same date.

Nothing about urokinase itself triggered the change. The code went because almost nobody billed it.

The 1999 Abbokinase warning was a separate event

Plenty of coding write-ups give the 1999 Abbokinase episode as the reason J3365 disappeared. That is wrong. The two events sit 26 years apart and are unconnected.

FDA inspections found manufacturing deficiencies at the production facility. FDA then issued an Important Drug Warning letter around January 25, 1999. Abbott Laboratories halted shipments of Abbokinase from December 1998 into early 1999.

That was a supply interruption, not a permanent market withdrawal. FDA reapproved Abbokinase in 2002. The product stayed on the US market afterward, later sold as Kinlytic.

So drug availability and code status moved on separate tracks. J3365 stayed a valid HCPCS code through the 1999 shipment halt, through the 2002 reapproval, and for more than two decades after that.

This matters for audit responses. If a payer or auditor questions a J3365 line from a 2015 or 2023 date of service, the code was correct at the time. Validity turns on the deletion date, not on the 1999 news.

How to bill urokinase for 2026 dates of service

The 2026 update deleted J3365 without issuing a specific replacement J-code for urokinase. The table below sets out the code path by date of service. Always check payer-specific guidance with the relevant MAC or commercial payer.

Important note on J3490: using J3490 for an unclassified drug requires supporting documentation. Payers expect the drug name, National Drug Code (NDC), dosage, and route in the claim narrative or attached records.

Without that detail, J3490 lines draw a high rate of documentation and medical necessity denials. Confirm the current crosswalk with the CMS Physician Fee Schedule or your MAC before you submit.

Medicare reimbursement for J3365

J3365 carries no 2026 reimbursement rate because the code is deleted. It will not appear in current Physician Fee Schedule or ASP drug pricing files. The table below covers the payment methodology that applied while the code was valid.

To price a urokinase product you are administering now, query the CMS Physician Fee Schedule search tool against the code you intend to bill. ASP pricing updates quarterly, so use the current quarter’s file for any prospective billing decision.

J3365 billing guidelines and applicable modifiers

Specific billing rules governed J3365 while it was valid. They still matter for anyone reconciling 2025 claims or answering a post-payment audit. Misapplied modifiers on older claims are a common source of recoupment demands during MAC review.

Common modifiers used with J3365

Documentation for J-series drug codes always includes the drug name and generic name, the NDC number, and the dosage given. It also needs the route, date of service, and the medical necessity behind the administration.

Pabau’s prescription management and clinical documentation tools hold the detail payers expect on injectable drug claims.

Place of service and units of service

• Place of service: urokinase IV infusion was usually billed in hospital outpatient (POS 22) or inpatient (POS 21) settings. Physician office billing (POS 11) was uncommon given the monitoring the drug required.
• Units of service: one unit equaled one 250,000 IU vial. A patient who received 500,000 IU generated two units on that claim line.
• Accompanying administration code: J3365 was billed alongside the infusion administration CPT code, 96365 for the initial hour and 96366 for each additional hour. It was never a standalone line.

ICD-10 codes to pair with urokinase claims

A payer wants the diagnosis to explain why a thrombolytic was given. These are the ICD-10-CM codes that most often supported urokinase administration, whether the claim carried J3365 or now carries J3490.

• I26.09 — other pulmonary embolism with acute cor pulmonale.
• I26.99 — other pulmonary embolism without acute cor pulmonale.
• I82.401 — acute embolism and thrombosis of unspecified deep veins of the right lower extremity.
• I82.402 — the same condition in the left lower extremity.
• T82.868A — thrombosis of vascular prosthetic devices, implants, and grafts, initial encounter. This is the usual pairing for catheter clearance.

Code to the highest available specificity, and match laterality and encounter character to what the record says. A vague diagnosis on a high-cost drug line is one of the fastest routes to a medical necessity denial.

J3365 vs. related HCPCS drug codes

Billers working with thrombolytics need to tell J3365 apart from codes that remain active or cover similar clinical ground. The table below compares it with the codes referenced most often. Active drug-specific codes such as J3090 follow the same one-drug, one-descriptor pattern.

Use the AAPC HCPCS code lookup to confirm current status for any code in this table. The NLM HCPCS Level II API also gives programmatic access to current code data. That helps if you are building charge-master verification into a workflow.

How to handle J3365 claims across the 2026 cutover

Most HCPCS reference pages confirm the deletion and stop there. The harder question is what to do with claims, charge masters, and appeals that straddle January 1, 2026. Here is a practical sequence.

Step 1: Check the date of service against January 1, 2026

Pull the original claim and read the date of service first. Everything else follows from which side of the cutover it falls on. A denial that looks like a coding error is often a claim filed correctly for a 2025 service and scrubbed against the 2026 code set.

Step 2: Keep J3365 on 2025 dates of service

For a service on or before December 31, 2025, J3365 is the correct code and should stay on the claim. Do not “fix” it to J3490. Medicare’s timely filing limit generally runs 12 months from the date of service, so late 2025 encounters still have an open window.

Step 3: Move 2026 dates of service to J3490

For a service on or after January 1, 2026, replace J3365 with J3490 and attach the drug detail. Confirm the path with your MAC before resubmitting, because some contractors publish their own instruction. Reviewing medical billing compliance rules first protects the practice if the corrected claim is examined.

Step 4: Clear J3365 out of your charge master

Search your CDM, superbills, order sets, and saved claim templates for J3365 and J3364. Retire both entries or gate them behind a billing team review. This is the step that stops the same denial recurring next month.

Step 5: Prepare documentation and track denials

Gather the physician order, nursing administration record, drug label with NDC, infusion notes, and the imaging that confirmed the PE or DVT. That package supports any corrected claim or audit response. On the corrected claim, note “Corrected Claim” and set the claim frequency code (CLM05-3, usually “7”).

Corrected claims for newly deleted codes sometimes draw a second denial even when refiled correctly. Escalate through the MAC appeals process if that happens.

Keep a dedicated AR log for J3365 lines so you can show good-faith remediation to an auditor. Claims management software with denial tracking and appeal workflows makes that far more manageable.

Documentation requirements for injectable drug claims

The documentation requirements are identical whether you are reconciling a 2025 J3365 claim or billing urokinase under J3490 today. Payers expect a complete clinical record for every injectable drug claim. That record has to support medical necessity plus the specific drug, dose, and route billed.

The elements a J-code claim needs on file:

• Physician order: signed, naming the drug, dose, frequency, and route.
• Diagnosis: the ICD-10-CM codes covered above, establishing medical necessity for thrombolysis.
• Drug administration record: nursing or infusion notes with the time administered, dose given, lot number, and patient response.
• NDC number: required on the claim by most payers, and it must match the product given.

Practices running infusion services alongside other clinical work benefit from IV therapy EMR software. Structured documentation captures NDC and dosage data at the point of care rather than reconstructing it later.

That cuts the work of assembling an audit package. The same discipline pays off in functional medicine practices billing vitamin and mineral infusions.

How Pabau keeps deleted codes like J3365 off your claims

A retired code usually announces itself with a denial. The charge master still lists it, and a staff member picks it from a familiar dropdown. The claim goes out carrying a code that expired weeks earlier, and someone reworks it by hand.

Pabau builds the claim from the clinical record instead. Drug administration is captured at the point of care with the dose, route, and NDC attached. The claim mirrors the record, so nobody retypes codes from memory days later.

Claims go out through our Claim.MD integration, the clearinghouse we submit through, with the supporting detail attached. Denials come back into a tracked queue with the reason code visible. You can see which codes generate rejections and fix the source entry once, rather than claim by claim.

Every Pabau subscription includes the full feature set. Clinical records, claims, and reporting all sit in the same system from your first week. A code-set change like the 2026 update becomes one housekeeping task instead of a month of rework.

Managing injectable drug billing in your practice?

Pabau helps practices keep retired codes off claims, track drug administration records, and stay audit-ready. See how it works for IV therapy and injectable drug billing.

Book a demo

Conclusion

One date decides how you bill urokinase. J3365 stays correct for services through December 31, 2025, filed inside the payer’s window. J3490 with full drug detail is the path from January 1, 2026.

CMS deleted 101 unused codes in the January 2026 update, J3364 and J3365 among them. Codes flagged “no maintenance” are the ones to watch, because they can sit dormant for years and then vanish in a single release.

The 1999 Abbokinase warning letter is a different story, so leave it out of any appeal. Abbott halted shipments, FDA reapproved the product in 2002, and it stayed on the US market.

Clear both codes out of your charge master before the next claim run, and the same denial stops coming back. Book a demo to see how Pabau captures drug administration records and submits claims with the detail payers expect.

Continue your research

Billing somatropin under a J-code? J2941 sets out the units, documentation, and payer rules for that drug.

Running an infusion suite? J2323 walks through natalizumab billing and the records payers ask for.

Billing the infusion fluids as well as the drug? J7120 explains how Ringer’s lactate is coded and paid.

Waiting on approvals for high-cost drugs? Prior authorization software shows how practices track requests and cut turnaround time.

Billing nursing time alongside the drug? T1001 covers nursing assessment claims and the documentation behind them.

Frequently asked questions

More on billing, pricing, and modifiers