Medicare and the tetanus shot: Part B vs Part D, the 2023 Inflation Reduction Act, and out-of-pocket
Part B vs Part D, the rule
| Trigger | Part | Cost-share | Source |
|---|---|---|---|
| Treatment for an injury (puncture wound, animal bite, deep cut) | Part B (medical) | Standard Part B deductible + 20% coinsurance; Medigap typically covers the 20% | [4][5] |
| Routine booster (10-year ACIP schedule, no recent injury) | Part D (drug) | $0 since January 1, 2023 (Inflation Reduction Act) | [1][2] |
| Pregnancy Tdap (extremely rare under Medicare) | Part B preventive (under maternity care) | $0 in-network | [3] |
What counts as "for an injury" under Part B
Documentation matters. To bill under Part B, the shot must be tied to a specific injury claim. Routine "I am 10 years overdue, please give me a booster" does not qualify under Part B even if the visit happens at a doctor's office. The correct billing route for routine boosters is Part D, which is now $0 under the IRA.
The 2023 Inflation Reduction Act change, in detail
As of January 1, 2023, ACIP-recommended Part D vaccines have no deductible and no copay for enrollees.[1] Before 2023, costs varied by Part D plan and could exceed $100 for Tdap. HHS ASPE reports show that vaccine use by Part D enrollees increased measurably after the cost-sharing elimination.[2] The change applies to all ACIP-recommended adult vaccines, not just tetanus, but the Tdap and Td effect is among the most visible because tetanus is the adult-vaccine line that touches the largest share of Medicare beneficiaries on a 10-year cycle.
Medigap and Medicare Advantage
- Medigap: fills the 20% Part B coinsurance for injury-related shots. Patients with most Medigap plans pay $0 out-of-pocket for an injury-billed Tdap.
- Medicare Advantage (Part C): bundles Part B and (usually) Part D and follows the same coverage rules. The IRA Part D change applies to MA-PD plans. Verify the specific plan's vaccine network before scheduling.
How to access $0 Part D vaccines
Most major pharmacy chains (CVS, Walgreens, Walmart, Costco, Sam's Club, Rite Aid, Kroger) process the Part D claim at the counter. Bring the Part D insurance card. The pharmacy bills directly; the patient walks out without paying anything.
What if the pharmacy says "not covered"
This is typically a billing or network issue. Steps in order:
- Confirm the pharmacy is in the patient's Part D plan network
- Confirm the vaccine is on the plan's formulary (Tdap and Td are universal)
- Call the Part D insurer directly
- If the insurer cannot resolve, try a different in-network pharmacy
Annual Wellness Visit
Tetanus is not on the standard Medicare Annual Wellness Visit checklist of covered preventive services. However, the patient can bring it up during the visit and the provider can administer the booster, billed under Part D. The AWV itself is covered with no cost-sharing under Part B.[3]
Adjacent reading
References cited on this page
- [1]Inflation Reduction Act: Vaccine Cost-Sharing for Medicare Part D Enrollees. HHS Assistant Secretary for Planning and Evaluation (ASPE). January 2023. https://aspe.hhs.gov/reports/medicare-part-d-vaccine-coverage
- [2]Medicare Part D Enrollee Vaccine Use After Elimination of Cost-Sharing. HHS ASPE. September 2024. https://aspe.hhs.gov/reports/part-d-vaccine-cost-sharing
- [3]Medicare Coverage of Vaccines. Medicare.gov / CMS. Accessed April 2026. https://www.medicare.gov/coverage/vaccines
- [4]LCD - Immunizations (L34596). CMS / Noridian. Accessed April 2026. https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?LCDId=34596
- [5]Tetanus and diphtheria toxoids vaccine billing under Medicare Part B and Part D. Noridian Healthcare Solutions. Accessed April 2026. https://med.noridianmedicare.com/web/jeb/topics/preventive-services/immunizations