ICD-10-CM 2027
ICD-10 code for thyroid insufficiency
From the official ICD-10-CM alphabetic index entry “Insufficiency, insufficient › thyroid (gland) (acquired)”. Page updated September 29, 2026.
About coding thyroid insufficiency
The ICD-10-CM code for thyroid insufficiency is E03.9 (Hypothyroidism, unspecified). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on E03.9.
Within E03, choose E03.9 (Hypothyroidism, unspecified) only when documentation doesn't support a more specific option: congenital hypothyroidism with diffuse goiter (E03.0), congenital hypothyroidism without goiter (E03.1), hypothyroidism due to medicaments and other exogenous substances (E03.2), postinfectious hypothyroidism (E03.3), atrophy of thyroid (acquired) (E03.4), myxedema coma (E03.5) and other specified hypothyroidism (E03.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 643 (Endocrine Disorders with MCC, relative weight 1.6139), DRG 644 (Endocrine Disorders with CC, relative weight 1.0044) and DRG 645 (Endocrine Disorders without CC/MCC, relative weight 0.7459), in MDC 10 (Endocrine, Nutritional and Metabolic Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific thyroid insufficiency codes (official index)
- congenital E03.1 — Congenital hypothyroidism without goiter
Common questions about thyroid insufficiency ICD-10 codes
What is the ICD-10 code for thyroid insufficiency?
- E03.9 — Hypothyroidism, unspecified. More specific codes apply when the documentation supports them: E03.1.
What is the ICD-10 code for congenital thyroid insufficiency?
- E03.1 — Congenital hypothyroidism without goiter.
Is E03.9 billable?
- Yes. E03.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can E03.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict E03.9 as a principal diagnosis.
Is E03.9 a CC or MCC?
- No. E03.9 is neither a CC nor an MCC under MS-DRG v44.0.