Does T21.40XA require prior authorization?

No, T21.40XA does not require prior authorization (high confidence). Code is covered without prior authorization.

`T21.40XA` — Corrosion of unspecified degree of trunk, unspecified site, initial encounter

ICD-10-CM

No Prior Auth Required

Code is covered without prior authorization (high confidence)

Billing and coding for immunizations must follow the coverage indications, limitations, and medical necessity criteria set forth in the associated Local Coverage Determination LCD L34596 (Immunizations).
The article provides billing/coding guidance that complements LCD L39400; use the documentation, prior authorization, and claim submission requirements specified in LCD L39400 and the local contractor's instructions.
Document the injury or exposure details and the clinician's determination that the encounter meets criteria for post-exposure vaccination (e.g., wound characteristics, exposure type).
Document patient immunization history, including dates of primary immunization and most recent booster, to support tetanus and rabies vaccine decisions.

No specific clinical indications are listed in this article; follow the Local Coverage Determination (LCD) L39400 for indications for magnesium testing or services.
When the patient has not been previously immunized for rabies, coverage includes RIG (half IM and half wound on day 0) plus HDCV on days 0, 3, 7, 14, and 28.
Vaccinations are covered only when directly related to treatment of an injury or direct exposure to a disease/condition listed in this policy.
Preventive immunizations are covered for pneumococcal, hepatitis B, and influenza vaccines.
Tdap or Td vaccines are covered when given for an acute injury in a person who is incompletely immunized for tetanus.
For tetanus-prone wounds, tetanus toxoid (booster) should be administered if the patient has not had a booster dose within the past 5 years.

A56900 — Billing and Coding: Immunizations

J05

L34596 — Immunizations

J05

A59186 — Billing and Coding: Magnesium

L39400 — Magnesium

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