Does S90.421A require prior authorization?

No, S90.421A does not require prior authorization (high confidence). Code is covered without prior authorization.

`S90.421A` — Blister (nonthermal), right great toe, initial encounter

ICD-10-CM

No Prior Auth Required

Code is covered without prior authorization (high confidence)

Claims must include a valid ICD-10-CM diagnosis code that best describes the condition prompting the immunization; claims without a valid diagnosis code will be returned as incomplete under Section 1833(e).
When a referring/ordering physician is required, the name and NPI of that physician must be reported on the claim.
For outpatient services likely to be noncovered, use ABN procedures: use modifier -GA with a signed CMS‑R‑131 ABN (or -GZ if no ABN), and for Part A submissions include occurrence code 32 and the ABN date.
Hospital inpatient claims must report principal diagnosis in UB‑04 FL67 and admitting diagnosis in FL69; up to eight additional ICD-10-CM codes in FL67A‑67Q as applicable.

One tetanus booster dose is covered for a patient who completed primary immunization, has sustained a high‑risk wound (anaerobic conditions or probable exposure to tetanus spores), and has not received a booster within the past 5 years.
For clean, minor, uncontaminated wounds, a tetanus booster is covered only if the last booster was >10 years ago (booster every 10 years for most recipients).
Tetanus toxoid injections (including primary series completion) are covered when given for an acute injury if the patient has not received primary immunization or the patient's primary immunization status is unknown; unknown/uncertain histories should be treated as unvaccinated.
For inadequately vaccinated patients of any age, completion of the primary tetanus vaccination series should be ensured at discharge or follow-up after an injury and is covered in that context.
A valid ICD-10-CM diagnosis code that best describes the patient’s condition for which the debridement service was performed must be reported on the claim.
When a service requires a referring or ordering physician, the name and NPI of the referring/ordering physician must be reported on the claim.

A56900 — Billing and Coding: Immunizations

J05

L34596 — Immunizations

J05

A52438 — Billing and Coding: Tetanus Immunization

A56459 — Billing and Coding: Debridement Services

L34032 — Debridement Services

Ask Verity about documentation requirements, denial risks, or coverage in your state.