T80.62XAOther serum reaction due to vaccination, initial encounter

T80.62XA is the ICD-10-CM diagnosis code for other serum reaction due to vaccination, initial encounter. It belongs to category T80 (complications following infusion, transfusion and therapeutic injection), block T80-T88 (complications of surgical and medical care, not elsewhere classified) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 791 (Prematurity with Major Problems, relative weight 4.1075), DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), DRG 915 (Allergic Reactions with MCC, relative weight 1.6558) and DRG 916 (Allergic Reactions without MCC, relative weight 0.6928), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period) and MDC 21 (Injuries, Poisonings and Toxic Effects of Drugs), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 999.52 (other serum reaction due to vaccination).