The LCD for my local MAC states:
"The following immunizations are covered post-exposure:
Tetanus, Diphtheria and Pertussis (Tdap) Vaccines and Tetanus Diphtheria (Td) Vaccines
These injections are covered when given for an acute injury to a person who is incompletely immunized.
1. Recommendations on tetanus prophylaxis are based on the condition of the wound and the patient's immunization history.
a. For more serious wounds, toxoid should be administered if the patient has not had a booster dose within the past 5 years.
b. A wound with any of the following clinical features is a tetanus-prone wound: more than 6 hours old; stellate; avulsion; abrasion; greater than 1 cm deep; injury due to missile, crush, burn, or frostbite; signs of infection; devitalized tissue; or a wound which affords anaerobic conditions or which has been incurred in a circumstance with probability of exposure to tetanus spores.
c. In cases of clean, minor wounds, tetanus toxoid should be administered only if the patient has not had a booster dose within the past 10 years.
2. When a patient has not received primary immunization or the primary immunization status is not known, and the patient has sustained a high-risk wound, administration of Tdap is recommended. Administration of Td may be appropriate based on the time since the patient received their last Tdap and the severity of the wound.
3. When a tetanus booster is given to a patient in the absence of an injury/potential exposure, the injection does not meet the coverage criteria for Medicare (even though it may be appropriate preventative treatment). Preventative services should not be billed to Medicare."
.... "Documentation Requirements
Documentation supporting the medical necessity of this item, such as
diagnosis codes, must be submitted with each claim. Claims submitted without such evidence will be denied as being not medically necessary.
Documentation in the progress notes must identify the exposure, describe the wound, describe the immunization status of the patient, and be available if requested. "
"... covered when:
- There has been direct exposure of the associated disease to the patient,
and
- There is significant risk that the patient could contract the disease as a result of the exposure."