T37.9Poisoning by, adverse effect of and underdosing of unspecified systemic anti-infective and antiparasitics

T37.9 is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of unspecified systemic anti-infective and antiparasitics. It belongs to category T37 (poisoning by, adverse effect of and underdosing of other systemic anti-infectives and antiparasitics), block T36-T50 (poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 6 subcodes must be used instead.

Within T37, choose T37.9 (unspecified systemic anti-infective and antiparasitics) only when documentation doesn't support a more specific option: sulfonamides (T37.0), antimycobacterial drugs (T37.1), antimalarials and drugs acting on other blood protozoa (T37.2), other antiprotozoal drugs (T37.3), anthelminthics (T37.4), antiviral drugs (T37.5) and other specified systemic anti-infectives and antiparasitics (T37.8).

Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.

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