CPT code 90674 – Cell-cultured quadrivalent flu vaccine

Key takeaways

CPT code 90674 covers Flucelvax Quadrivalent, a cell-cultured, four-strain, preservative-free 0.5 mL flu vaccine licensed for patients 6 months and older.

Flucelvax switched to a trivalent formula for the 2024–25 season and now bills under 90661. Use 90674 for quadrivalent doses and earlier dates of service.

The vaccine and its administration bill separately: 90674 for the product, plus 90471 for most commercial payers or G0008 for Medicare.

Medicare Part B covers the flu vaccine with no deductible or coinsurance. Every claim needs the 11-digit NDC in the shaded area of Box 24A.

Pabau, the practice management platform we build, records each vaccine lot against the patient and sends US claims through Claim.MD.

CPT code 90674: Official descriptor and quick-reference facts

CPT code 90674 describes influenza virus vaccine, quadrivalent (ccIIV4), derived from cell cultures, subunit, preservative and antibiotic free, 0.5 mL dosage, for intramuscular use.

The American Medical Association publishes this descriptor as part of the CPT code set. Each part of it narrows the product: cell-cultured rather than egg-based, four strains, a preservative-free single dose, and IM injection only.

Check the date of service before you bill it. US flu vaccines moved to trivalent formulas for the 2024–25 season, and trivalent Flucelvax bills under 90661. The CDC’s CPT-to-CVX code table still lists 90674, so it stays valid for quadrivalent doses and for claims on earlier dates.

What CPT code 90674 covers and what it excludes

CPT code 90674 covers the Flucelvax Quadrivalent vaccine product itself. It does not bundle the injection, so a flu shot always produces at least two claim lines.

What 90674 includes: The cost of a Flucelvax Quadrivalent single-dose syringe, covering four influenza strains made in cell culture. The code captures the product alone.

What 90674 excludes:

• Immunization administration: Always billed separately under CPT 90471 (first vaccine) or 90472 (each additional injectable vaccine in the same encounter)
• Trivalent Flucelvax: The formula used from the 2024–25 season onward bills under CPT 90661
• Multi-dose Flucelvax Quadrivalent vials: These bill under CPT 90756, the antibiotic-free ccIIV4 code
• Egg-based quadrivalent products: These bill under CPT 90686 or 90688, not 90674
• Recombinant influenza vaccines: Flublok Quadrivalent (RIV4) bills under CPT 90682, and trivalent Flublok under 90673
• High-dose or adjuvanted flu vaccines: Fluzone High-Dose and Fluad bill under separate codes entirely

The most common bundling error is submitting 90674 and a same-day E/M service without modifier 25 on the visit code. The vaccine line pays, but the visit is denied. Place modifier 25 on the evaluation and management code, not on 90674.

Documentation requirements before submitting a 90674 claim

Every 90674 claim needs a matching documentation trail in the patient record before it leaves the practice. Leaving out any of these elements invites a denial.

1. NDC number: The National Drug Code for the Flucelvax product administered must appear on the claim. A missing or invalid NDC is a top denial trigger for vaccine claims. On the CMS-1500, enter it in the shaded area of Box 24A after the N4 qualifier, as 11 digits with no hyphens (5-4-2 layout)
2. Lot number and expiration date: Document both in the EHR for the administered dose. Payers and state immunization registries require this for adverse event tracing
3. Vaccine Information Statement (VIS) date: Record the date the VIS was given to the patient. Some payers audit this field on recoupment reviews
4. Route and injection site: Record IM administration and the anatomical site (deltoid muscle preferred for adults, anterolateral thigh for infants and young children)
5. Administering provider: The name and NPI of the person who gave the vaccine must be in the record. This matters when nursing staff administer under a physician order

A superbill that lists the NDC beside the vaccine charge saves staff from copying it off the carton, which is where transcription errors creep in.

In Pabau, the practice management platform we build, each vaccine in stock carries its batch number and expiry date. The lot is recorded against the patient and the appointment, so every claim traces back to a specific vial.

Which administration code to bill alongside CPT code 90674

CPT code 90674 never travels alone. The vaccine code and an administration code always appear as a pair on the claim, and your claims management software has to carry both lines.

The right pair depends on what else happens at the visit and on who pays.

Medicare works differently. Flu vaccine administration under the Part B preventive benefit bills under HCPCS G0008, not CPT 90471. Practices that default to 90471 out of habit see Medicare underpay or deny the administration line, so confirm the payer before you choose the code.

CPT code 90674 vs 90661, 90756, 90686, and other flu vaccine codes

Several influenza vaccine codes cover cell-cultured, egg-based and recombinant products, and they split again by strain count and presentation. Picking the wrong one, then sending an NDC that belongs to a different product, creates the most audit exposure in vaccine billing. The map below shows where 90674 sits.

The table adds the products behind each code, so you can check a carton against the claim line.

The NDC on the product dictates the CPT code. A Flucelvax Quadrivalent syringe NDC resolves to 90674, and a trivalent Flucelvax NDC resolves to 90661. If the NDC belongs to Fluzone Quadrivalent, the correct code is 90686. Submitting 90674 with a Fluzone NDC draws a denial because the product and the code don’t form a recognized pair.

Medicare reimbursement for CPT code 90674

Medicare Part B covers CPT code 90674 as a preventive benefit, with no deductible and no coinsurance for the beneficiary. That rule comes from the Medicare statute itself, which covers flu vaccine under Part B with no cost-sharing. The ACA’s preventive mandate is a separate rule that applies to commercial plans.

Medicare doesn’t price the vaccine from the Physician Fee Schedule. CMS pays flu vaccines at 95% of the average wholesale price and publishes the rates each season on its vaccine pricing page. Check the current-season allowable there before billing, because a fixed dollar figure goes stale every season.

Submit 90674 on the CMS-1500 with the NDC in the shaded area of Box 24A and the CPT code in Box 24D. The rendering provider’s NPI goes in Box 24J. Use G0008, not 90471, for the administration line.

Practices that bill electronically can route these claims through Claim.MD to the payers on its network, then post payments from the electronic remittance advice.

Modifiers for CPT code 90674

Two modifiers come up in 90674 billing, and each targets a different payer or program scenario. Using the wrong one, or leaving out a required one, produces denials that look unrelated to the vaccine itself.

Modifier SL applicability varies by state Medicaid program. Some states require it on both the vaccine and administration codes, while others require it on the administration code alone. Confirm with your state Medicaid provider manual before billing. VFC-eligible patients also need VFC eligibility screening documented in the chart, whichever modifier you use.

Common denial reasons for CPT code 90674 and how to fix them

Most 90674 denials are preventable. A workflow that catches these patterns before submission recovers more revenue than a reactive appeals process.

Review remittance denial codes after every vaccine billing cycle, not just on individual claim exceptions. Flu season packs a high volume of claims into a short window, which makes patterns faster to spot than one-off appeals. Clean claim submission upstream, especially NDC accuracy at charge entry, cuts the volume that needs correcting later.

ICD-10 codes to pair with CPT 90674

The standard diagnosis code on an immunization-only visit billed with CPT code 90674 is Z23, the ICD-10-CM code for an encounter for immunization. It tells the payer this is a preventive encounter, which is what triggers zero cost-sharing on non-grandfathered commercial plans.

• Z23: Encounter for immunization. Use as the primary diagnosis on all routine flu vaccine visits
• Do not use: Symptom codes (cough, fever, fatigue), illness codes, or chronic condition codes as the primary diagnosis on a vaccine-only encounter. These override the preventive benefit and can trigger cost-sharing

A patient may come in for the flu vaccine and also have a chronic condition managed at the same visit. Sequence Z23 for the vaccine line and the chronic condition code for the E/M service. This keeps the vaccine’s preventive classification while still capturing the medical necessity of the visit.

Place of service and care setting considerations for CPT code 90674

The place of service code doesn’t change what Medicare pays for the 90674 product, which comes from the seasonal vaccine pricing file. It can change who bills the claim and how the administration line is paid. A wrong POS therefore tends to surface as an underpayment or a rejection rather than a clean denial.

Practices that vaccinate at community health fairs, employer onsite events, or long-term care facilities often default to POS 11. That code is wrong for those settings. Use the POS that reflects where the patient received the vaccine, not the practice’s billing address. A wrong POS usually shows up only during fee schedule reconciliation, not in the first claims review.

Coverage under private insurance, Medicaid, and the VFC program

Coverage rules for CPT code 90674 vary by payer type, so Medicare’s rules can’t be assumed to apply everywhere.

• Non-grandfathered commercial plans (ACA-compliant): Must cover ACIP-recommended vaccines, including the cell-cultured influenza vaccine, with no cost-sharing when given in-network
• Grandfathered commercial plans: Not subject to the ACA preventive mandate, so cost-sharing may apply. Verify benefit terms before waiving copay collection
• Medicaid: State programs vary substantially. Some state programs have their own vaccine billing rules or code lists. Confirm your state’s preferred code in the state Medicaid provider manual before billing 90674 to Medicaid
• VFC-eligible patients: The Vaccines for Children program supplies vaccine at no cost for eligible children through age 18 (Medicaid-eligible, uninsured, underinsured, or American Indian/Alaska Native). The practice bills the administration, and many states also want 90674 reported at no charge with modifier SL

How Pabau keeps flu vaccine claims tied to the vial

In many practices, flu shot billing still runs on manual steps. Someone reads the NDC off the carton, types it into the claim and hopes it matches the CPT line. When a vaccine changes formula, as Flucelvax did for 2024–25, those habits keep sending the old code.

Pabau stores the vaccine lot on the appointment itself. Your billing team can compare the product each patient received with the CPT line before the claim goes out, instead of after a denial.

US claims go out as CMS-1500 claims through Claim.MD, with eligibility checks before the visit and ERA remittances after it. Secondary claims run from the same patient record, so your billing team works one queue for the whole flu season.

Bill every flu vaccine from one patient record

Pabau records each vaccine lot and expiry date against the patient and sends US claims through Claim.MD. Eligibility checks and ERA remittances sit in the same place.

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Conclusion

Treat 90674 as a product code first and a flu code second. Read the vial, match the formulation, and check the date of service against the 2024–25 switch to trivalent before the claim goes out.

The pairing matters as much as the code. Every claim needs an administration line, G0008 for Medicare, Z23 as the diagnosis, and an 11-digit NDC with no hyphens. A minute of checking at charge entry costs far less than weeks of chasing denials in the middle of flu season.

To see how Pabau ties each vaccine lot to the patient record and sends flu claims through Claim.MD, book a demo.

Continue your research

Need to understand how claims reach the payer? Medical claims clearinghouse explains how clearinghouses validate, route, and report on vaccine and other professional claims.

Seeing repeated remittance adjustments you cannot decode? Claim.MD clearinghouse integration covers how Pabau’s clearinghouse partner handles ERA delivery and denial routing.

Want to reduce your overall denial rate across all codes? Revenue cycle management guide walks through the end-to-end RCM workflow from eligibility check through payment posting.

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