Patient had a prior influenza virus vaccine adverse reaction any time before or during the measurement period

Still listed by CMS but carries a termination date, so it is not valid for a current date of service.

Terminated with effect from 2020-12-31. This code was already terminated before the earliest quarterly file on record here, so the date it was first published is not recorded on this site. CMS still lists this code in the current quarterly file - it carries a termination date rather than being removed.