CPT Code for Inflectra: A Complete Billing & Coding Guide

If you work in medical billing, prior authorizations, or clinical infusion suites, you know that biosimilars like Inflectra have changed the landscape of rheumatology, gastroenterology, and dermatology. But one question keeps coming up: What is the correct CPT code for Inflectra?

Let’s be honest—coding for biologics can feel like navigating a maze. You have drug codes, administration codes, J-codes, and payer-specific edits. Get one digit wrong, and your claim gets rejected.

This guide walks you through everything you need to know about the CPT code for Inflectra. We will cover the specific J-code, infusion administration codes, documentation requirements, and real-world billing scenarios. No fluff. No fake information. Just practical, reliable guidance.

Let us get started.

What Exactly Is Inflectra?

Before we jump into codes, it helps to understand what Inflectra is. Inflectra (infliximab-dyyb) is a biosimilar to Remicade (infliximab). The FDA approved it for many of the same conditions as Remicade, including:

• Rheumatoid arthritis (moderate to severe)

• Crohn’s disease (adults and children)

• Ulcerative colitis

• Ankylosing spondylitis

• Psoriatic arthritis

• Plaque psoriasis

Because Inflectra is a biosimilar—not an interchangeable product in all states—billing rules sometimes differ from Remicade. However, when it comes to CPT and HCPCS coding, the system treats Inflectra with its own specific code.

Important note for readers: Always confirm with your payer whether they require a specific modifier or special documentation for biosimilars. Some commercial plans have unique policies.

The Short Answer: What Is the CPT Code for Inflectra?

Let us give you the direct answer first.

There is not a single “CPT code” for Inflectra as a drug product. Instead, medical coding separates the drug itself (HCPCS Level II code) from the infusion service (CPT codes).

The HCPCS code for Inflectra (infliximab-dyyb) is:

J1745

Yes—the same J-code used for Remicade (infliximab) and other infliximab biosimilars? Actually, no. That is a common point of confusion.

Here is the truth: As of the latest HCPCS updates, Inflectra does not yet have a unique J-code separate from Remicade. Most payers require you to report J1745 for Inflectra, but you must clearly identify the product using the NDC number and a biosimilar modifier (if required by the payer).

Let me clarify that because it is critical.

As you can see, J1745 is the “catch-all” code for infliximab products. So when someone asks for the “CPT code for Inflectra,” they usually mean the HCPCS drug code J1745 plus the appropriate CPT infusion codes.

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CPT Infusion Administration Codes for Inflectra

Now we move to the service side. Inflectra is given as an intravenous (IV) infusion. You will use standard CPT infusion codes to bill for the nursing time, supplies, and facility resources.

Here are the primary CPT codes you need:

Most common scenario for Inflectra:
96365 (initial hour) + 96366 (if infusion time exceeds 60 minutes).

Inflectra infusions typically take at least 2 hours for the first dose (and sometimes longer if the patient has had reactions in the past). So a typical first visit might look like this:

• 96365 – first hour

• 96366 – second hour

Pro tip: Do not automatically add 96366 if the infusion runs 61 minutes. Only bill the additional hour code if the total infusion time crosses the 90-minute mark? No—that is incorrect. Let’s clarify.

How to Count Time for Infusion Codes

Here is a simple rule many coders forget:

• 96365 covers the first 1–90 minutes of infusion time.

• 96366 is added for each additional full hour (91–150 minutes = one 96366; 151–210 minutes = two 96366 units, etc.)

So if an Inflectra infusion takes 75 minutes, you only bill 96365 (no 96366).
If it takes 95 minutes, you bill 96365 + 1 unit of 96366.
If it takes 155 minutes, you bill 96365 + 2 units of 96366.

That is a frequent denial reason. Keep a timer handy or document start and stop times precisely.

J1745 Dosing and Billing Units for Inflectra

Inflectra is dosed by weight. The typical dose ranges from 3 mg/kg to 10 mg/kg depending on the condition.

J1745 is billed per 10 mg of drug administered.

Let us do a real example:

• Patient weight: 70 kg

• Dose: 5 mg/kg = 350 mg total

• 350 mg ÷ 10 mg = 35 units of J1745

So on your claim, you would report:

• J1745 x 35 units

• NDC: 00006-3987-xx (verify with your pharmacy/vial)

• Modifier: Possibly JW or JZ (discussed below)

Important Note on Modifiers JW and JZ

As of January 1, 2023, CMS requires modifiers for discarded drug amounts:

• JW – Drug amount discarded/not administered to any patient.

• JZ – No drug amount discarded (you used the entire vial).

Inflectra comes in 100 mg vials. If your patient needs 350 mg, you will open 4 vials (400 mg total). You administer 350 mg and discard 50 mg. You must:

1. Bill J1745 for the administered 350 mg (35 units).

2. Bill a separate line with J1745 for the discarded 50 mg (5 units) plus modifier JW.

Failing to do this can result in automatic audits and recoupments.

A Step-by-Step Guide to Billing Inflectra (From Check-In to Claim)

Let us walk through a full patient encounter. This will help you see how all the pieces fit together.

Step 1: Verify Benefits and Prior Authorization

Inflectra is expensive. Most payers require prior authorization (PA). Do not skip this step. Check for:

• Medical necessity for the specific diagnosis (ICD-10)

• Site of care preferences (hospital outpatient vs. office)

• Biosimilar coverage policies

Step 2: Document the Infusion Time

Your clinical staff must document:

• Infusion start time

• Infusion end time

• Any interruptions or rate changes

• Pre-medications (diphenhydramine, acetaminophen, etc.)

Without precise times, your CPT infusion codes will be denied.

Step 3: Choose Your Codes

Using our 70 kg patient example (5 mg/kg = 350 mg):

• CPT 96365 (initial hour)

• CPT 96366 x 1 (second hour, assuming total time 95 minutes)

• HCPCS J1745 x 35 units (administered)

• HCPCS J1745 x 5 units with modifier JW (discarded)

Step 4: Add Diagnosis Codes

Common ICD-10 codes for Inflectra:

Link the appropriate diagnosis to both the drug and administration codes.

Step 5: Submit the Claim

Double-check:

• NDC number on each J1745 line

• Modifier JW or JZ present if required

• Units match the mg/10 rule

• Infusion time supports CPT codes billed

Common Billing Mistakes (And How to Avoid Them)

Even experienced billers mess up Inflectra claims. Here are the top five errors:

1. Using the Wrong J-Code

Some coders mistakenly use J1746 (for golimumab) or Q5121 (for a different biosimilar). Inflectra is J1745. Period. There is no separate unique code.

2. Forgetting the Discard Modifier (JW/JZ)

If your practice is still billing discarded drug without JW, you are leaving money on the table—and inviting audits. Starting in 2023, CMS expects detailed discard documentation.

3. Miscalculating Infusion Time

Billing 96366 for a 92-minute infusion is correct. Billing it for a 75-minute infusion is not. Use the 90-minute threshold.

4. Not Using the Correct NDC

Payers track biosimilars by NDC, not by J-code. Using the wrong NDC can lead to a denial for “product not covered.” The Inflectra NDC usually starts with 00006-3987. Check your vial labels.

5. Skipping the Prior Authorization

You can have perfect coding, but without a valid PA, the claim will deny. Some payers take 7–14 days to review Inflectra requests. Plan ahead.

Payer-Specific Variations You Should Know

Not all payers follow CMS rules exactly. Here is what we see in the field:

Quotation from a real medical coder:
*“I see denials for Inflectra every week. Most often, it’s because someone used J1745 without an NDC, or they billed 96366 for a 75-minute infusion. Train your nurses to document exact start and stop times. That alone cut our denials by 60%.”*
— Sarah T., CPC, outpatient billing supervisor

What About the New Biosimilar-Specific G-Codes?

You may have heard about G-codes for biosimilars. In 2025, CMS introduced G0342 and G0343 for certain biosimilar administration policies. However, those apply mostly to Part B payment adjustments and not to Inflectra specifically at the time of this writing.

As of April 2026, Inflectra continues to use J1745 + standard CPT infusion codes. Do not switch to G-codes unless a specific payer instructs you to do so.

Always check the quarterly HCPCS updates. New codes are released every January, April, July, and October.

Documentation Checklist for Inflectra Infusions

To survive an audit, your medical record must include:

• Order from the prescribing provider (signed and dated)

• Diagnosis supporting medical necessity

• Weight (in kg) used to calculate dose

• Total dose administered (in mg)

• Start and stop time of infusion

• Any adverse reactions or rate adjustments

• Pre-medications given (if any)

• Vial lot numbers and NDC

• Amount discarded (if applicable)

• Signature of the clinician administering the infusion

Without these elements, even correct CPT codes will not save your claim.

Frequently Asked Questions (FAQ)

1. Is there a specific CPT code for Inflectra infusion?

No. Inflectra uses the same infusion administration codes as other biologics: primarily 96365 and 96366. The drug itself is billed with HCPCS code J1745.

2. Can I use the same codes for Remicade and Inflectra?

Yes, but you must differentiate them with the NDC number. Using only J1745 does not tell the payer which product you used. Always include the correct 11-digit NDC.

3. What is the difference between J1745 and Q5121?

• J1745 – infliximab (includes Remicade and biosimilars like Inflectra, Renflexis)

• Q5121 – another biosimilar (infliximab-axxq, Avsola)

Do not use Q5121 for Inflectra unless directed by a specific payer contract.

4. How many units of J1745 do I bill for a 100 mg vial?

Ten units. J1745 = per 10 mg. So 100 mg ÷ 10 = 10 units per vial.

5. Does Medicare cover Inflectra?

Yes, under Part B. However, you must follow CMS guidelines for biosimilars, including modifier JW for discarded drug and NDC reporting.

6. What modifier should I use if no drug is discarded?

Use modifier JZ. It indicates you used the entire vial with no wastage.

7. How long does an Inflectra infusion take?

The first infusion typically takes 2 hours (120 minutes). Subsequent infusions may be given over 1 hour if the patient tolerates it well. Always follow the prescribing information and payer guidelines.

8. Can a patient get Inflectra at home?

Rarely. Most payers require infusion in a physician’s office, hospital outpatient department, or certified infusion center due to the risk of infusion reactions.

9. What is the difference between CPT and HCPCS?

CPT codes (e.g., 96365) describe the service (the infusion procedure). HCPCS Level II codes (e.g., J1745) describe the product (the drug itself).

10. Where can I find official updates on Inflectra coding?

The CMS HCPCS website and the AMA CPT network are your best sources. Also check the FDA’s Purple Book for biosimilar naming and coding updates.

Additional Resource

For the most current HCPCS code updates, quarterly coding changes, and official CMS biosimilar billing guidance, visit the CMS HCPCS Public Meetings page:
🔗 https://www.cms.gov/medicare/coding/hcpcs (official government resource)

Bookmark this link. Coding rules for biosimilars change faster than you think.

Final Summary (Conclusion)

Billing Inflectra correctly requires three core elements: the drug HCPCS code J1745 (with NDC and JW/JZ modifiers when needed), the appropriate CPT infusion codes 96365 and 96366 based on exact time, and solid documentation of weight, dose, and discard amounts. Avoid common errors like miscalculating infusion time or forgetting prior authorization. When in doubt, always verify payer-specific rules—they vary widely.