CPT code 90633 – Hepatitis A vaccine, pediatric 2-dose series

Key takeaways

90633 covers the pediatric and adolescent hepatitis A vaccine, supplied as 720 EL.U/0.5 mL or 25 U/0.5 mL.

90632 is the adult single-dose formulation, so the product administered decides the code, not the patient’s age alone.

Every 90633 claim line needs a paired administration code, either 90471 or 90460, on the same date of service.

When VFC supplies the vaccine, bill only the administration code and append modifier SL where the payer asks for it.

Medicare Part B does not cover hepatitis A vaccination preventively, so preventive doses go to the patient’s Part D plan.

CPT code 90633: Official descriptor and code definition

CPT code 90633 is the vaccine product code for hepatitis A, pediatric/adolescent dosage, for intramuscular use.

The code sits in the Vaccines and Toxoids section of the CPT codebook (range 90476-90759), maintained by the American Medical Association.

Two FDA-approved vaccine products map to this code: HAVRIX 720 EL.U/0.5 mL (GSK) and VAQTA 25 U/0.5 mL (Merck). Both are two-dose series formulations dosed at 0 and 6-18 months.

CPT 90633 vs 90632: Choosing the right hepatitis A vaccine code

90632 covers the adult hepatitis A vaccine, a single dose of 1440 EL.U/1.0 mL. 90633 covers the pediatric and adolescent formulation, a 2-dose series of 720 EL.U/0.5 mL. Picking the wrong one is the most common audit trigger on hepatitis A vaccine claims.

Select the code from the vaccine product administered, not from the patient’s age alone. An 18-year-old who receives the pediatric formulation still maps to 90633.

Required administration codes and claim structure

CPT code 90633 is a product-only code and cannot be submitted on its own. Every 90633 claim line requires a paired administration code on the same date of service.

• 90471 — first vaccine administered, with no counseling requirement
• 90472 — each additional vaccine on the same date, needed only when other vaccines are given
• 90460 — first vaccine with face-to-face counseling by a physician or qualified health professional, patient 18 and under
• 90461 — each additional vaccine component when 90460 applies

Use 90460 and 90461 only when documented counseling is provided and the patient is 18 or younger. For adult high-risk administration such as travelers, where 90633 is used off-label, 90471 is the standard pairing. Payers reject 90460 for patients over 18.

On the claim, sequence 90633 before the administration code. Some payers require them on separate claim lines, while others accept them on the same line. Check payer-specific billing manuals before submitting electronically through a clearinghouse.

Three questions asked at the point of care settle every line on the claim. The chart below takes them in the order a nurse meets them.

ICD-10 diagnosis codes to pair with 90633

Z23 (encounter for immunization) is the primary ICD-10-CM diagnosis code for hepatitis A vaccine administration. It must appear on every 90633 claim as the first-listed diagnosis.

Some commercial payers and state Medicaid programs accept additional risk codes as secondary diagnoses alongside Z23, such as international travel or food-handler status. Check the payer’s own diagnosis requirements first, and confirm the wording against the current ICD-10-CM code reference.

When each modifier applies

Most 90633 claims submit without a modifier. Three modifiers apply in specific circumstances, and omitting them when they are required causes preventable denials.

Medicare and Medicaid coverage for the hepatitis A vaccine

Medicare Part B does not cover hepatitis A vaccination as a preventive service. That high-risk carve-out belongs to the hepatitis B vaccine instead. Part B pays for a hepatitis A dose only when it treats an injury or a documented exposure to the virus. Preventive and risk-based doses sit under the Part D drug benefit.

• Medicare Part B: No preventive coverage. Part B pays only when the vaccine treats an injury or a documented exposure, which makes it a treatment claim rather than an immunization claim.
• Medicare Part D: Covers preventive hepatitis A vaccination as a prescription drug benefit, including the product and its administration. Bill the patient’s Part D plan, not Part B.
• Medicare Advantage: Vaccine coverage usually runs through the plan’s own drug benefit. Verify plan-level policy before billing.
• Medicaid: Typically covers 90633 for children under the Vaccines for Children (VFC) program at no charge to the family. Adult Medicaid coverage varies by state.
• Commercial payers: Most cover hepatitis A vaccine as a preventive service under ACA mandates for patients through age 18. Adult coverage depends on the plan and on documented risk.

Practices with a high volume of pediatric immunizations should verify VFC enrollment status annually. Billing 90633 to Medicaid for a VFC-eligible patient, when the vaccine was government-furnished, is an audit risk. Confirm your payer mix before you set default billing rules for this code.

Fee schedule and reimbursement rates for 2026

CMS publishes a Medicare physician fee schedule allowable for 90633 each year. The product code carries a modest allowable on its own, and the administration code is billed separately with an allowable of its own.

Preventive hepatitis A doses fall under the Part D drug benefit. That makes the Part B allowable a reference point rather than the rate most 90633 claims are paid at. Private payer rates typically exceed Medicare allowables for vaccine product codes.

VFC pricing is set separately by the CDC and does not reflect payer reimbursement. Under VFC, the practice bills only for administration. Rates change every January 1, so pull current figures from the CMS Physician Fee Schedule Look-Up Tool before quoting allowables to clinical staff.

Documentation requirements for a clean 90633 claim

A complete medical record and clean claim for 90633 requires specific data elements. Missing any of the following is the fastest path to a downcode or an audit request.

• Vaccine product name and NDC: HAVRIX or VAQTA, with the NDC required by many payers and every Medicaid program. Include it in box 19 or the matching electronic field.
• Lot number and expiration date: Required in the immunization record, and requested by some payers on appeal.
• Dose administered: 0.5 mL for 90633. Document that the pediatric formulation was used.
• Site of injection: Deltoid or anterolateral thigh, recorded in the clinical note.
• Patient age: Confirms pediatric eligibility for 90633 over 90632, so it has to be in the record.
• Dose number in series: First or second dose of the 2-dose series, which matters for duplicate-billing edits.
• Administering provider NPI: Required on the claim, with the ordering provider NPI added where the two differ.
• VFC eligibility status: Where the dose is VFC-supplied, document eligibility and use modifier SL.

Those fields are also what the broader clean claim requirements come down to. Digital forms that capture lot, NDC and dose-series data at the moment of administration keep the record out of a second system. Copying a paper immunization record onto a claim by hand is where NDC errors start.

Top reasons 90633 claims are denied, and how to fix them

Six denial patterns account for most 90633 rejections. Each has a corrective action that prevents recurrence, rather than simply fixing the individual claim.

Sorting a quarter’s 90633 rejections by payer, provider and charge-capture step usually points at one broken step rather than scattered coder error. Review them quarterly and fix the step, not the individual claims.

Vaccines for Children (VFC) program billing rules

CPT 90633 is a VFC-eligible vaccine code under the CDC’s Vaccines for Children program. When a VFC-supplied vaccine is administered, one billing rule overrides the rest: bill only the administration code, never the product code.

• Do not bill 90633 to the payer when the VFC program furnished the vaccine, because the federal government has already paid for the product
• Bill only 90471 or 90460 for the administration, to the payer or the patient
• Append modifier SL to the administration code where the payer or state Medicaid program requires it to flag a state-supplied vaccine
• Document VFC eligibility in the patient record: Medicaid-eligible, uninsured, underinsured, American Indian or Alaska Native, or CHIP-eligible
• Never charge VFC-eligible families for the vaccine product itself, which is a program violation

Practices that treat 90633 as a catch-all vaccine charge are the ones this rule catches. If your practice is VFC-enrolled, your billing system should separate purchased stock from VFC stock at the charge-capture step. Software built for billing teams tracks the stock source, so the wrong product code never reaches the payer.

How Pabau keeps vaccine charges complete before the claim leaves

Most 90633 denials are made at the charge-capture screen, not in the billing office. A nurse records the dose in the immunization log, and someone rebuilds the charge from that log hours later. By then the NDC, the lot number and the stock source have to be remembered rather than read.

Practice management software like Pabau links the vaccine product to its required administration code. A 90633 charge cannot be saved without 90471 or 90460 beside it. The immunization record carries the NDC, lot number and dose number onto the claim, and VFC stock is flagged at the moment it is selected.

Claims then go out through our Claim.MD clearinghouse integration, with eligibility checked first. Coverage problems surface before the visit rather than six weeks later in a denial. Billing staff work exceptions instead of rebuilding charges from the chart.

Reduce vaccine billing errors before claims leave the practice

Pabau captures CPT codes, administration codes, and NDC numbers at the point of care, then submits clean claims through our Claim.MD clearinghouse integration. Fewer denials, less rework.

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Conclusion

The preventable 90633 denials share one cause: a charge-capture workflow that does not enforce the product-administration pairing or separate VFC stock from purchased vaccine. Fix that step and most of the rework disappears before it starts.

The Medicare rule is worth committing to memory on its own, because it costs practices whole claims. Part B is not the destination for a preventive hepatitis A dose, and no amount of supporting diagnosis coding will make it one.

Pabau’s claims management tools link CPT product codes to their required administration codes. They capture the NDC and lot number at administration, then submit through Claim.MD with real-time eligibility checks. Book a demo to see how vaccine billing runs when the claim is built at the point of care.

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