See following response posted by revcycleintelligence.com. I've copied an article they wrote that directly answers your question and have included the link below
"The American Medical Association (AMA) announced a Current Procedural Terminology (CPT) code set update to include a code for administering a third dose of Pfizer’s COVID-19 vaccine in children 5 through 11 years of age.
CPT code 0073A was added to the official CPT code set, effective immediately. The addition comes on the heels of the Food and Drug Administration’s (FDA’s) decision to expand Pfizer’s COVID-19 vaccine emergency use authorization to include a third primary series dose of the vaccine in children who are immunocompromised.
The FDA’s decision to allow immunizers to boost certain children susceptible to poor outcomes if they become infected with COVID-19 is a welcome action, AMA stated.
'Although children 5 and older have been eligible to receive the Pfizer-BioNTech COVID-19 vaccine since November 2021, vaccination rates among children and adolescents remain low,” said Gerald E. Harmon, MD, president of the AMA. “We strongly urge all parents to get their children fully vaccinated as soon as they are eligible.'
The vaccine administration code added to the CPT code set will enable immunizers to document and bill payers for the third dose. AMA said the code will also assist with reporting and tracking of vaccinations, especially since the code specifically describes the administration of a third dose of the Pfizer vaccine in paediatric patients.
So far, AMA has updated the CPT code set to give immunizers the tools to document administration of most COVID-19 vaccines, including those created by AstraZeneca, Janssen (Johnson & Johnson), Moderna, and Novavax. The CPT codes are effective as long as the FDA approves or provides emergency use authorization for the doses.
Currently, the CPT code set includes 29 Category 1 codes for approved COVID-19 immunizations.
The new CPT code (0073A) was published to the code set on Jan. 12, 2022, and become effective Jan. 3, 2022. "