T38.1Poisoning by, adverse effect of and underdosing of thyroid hormones and substitutes

T38.1 is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of thyroid hormones and substitutes. It belongs to category T38 (poisoning by, adverse effect of and underdosing of hormones and their synthetic substitutes and antagonists, not elsewhere classified), 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 1 subcodes must be used instead.

Within T38 (poisoning by, adverse effect of and underdosing of hormones and their synthetic substitutes and antagonists, not elsewhere classified), T38.1 is specifically for poisoning by, adverse effect of and underdosing of thyroid hormones and substitutes. Related codes cover glucocorticoids and synthetic analogues (T38.0), antithyroid drugs (T38.2), insulin and oral hypoglycemic [antidiabetic] drugs (T38.3), oral contraceptives (T38.4), other estrogens and progestogens (T38.5), antigonadotrophins, antiestrogens, antiandrogens, not elsewhere classified (T38.6), androgens and anabolic congeners (T38.7), other and unspecified hormones and synthetic substitutes (T38.8) and 1 more.

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.