Hypothyroidism ICD-10-CM Codes
ICD-10-CM codes for hypothyroidism, including congenital hypothyroidism, postprocedural hypothyroidism, and myxedema coma.
Coding Guidance for Hypothyroidism
E03.9 (hypothyroidism, unspecified) is the default code for acquired hypothyroidism when neither the cause nor a more specific type is documented.
Use E03.1 for congenital hypothyroidism, E89.0 for postprocedural hypothyroidism following thyroid surgery or ablation (with the procedure history captured by Z90.- codes where applicable), and E03.5 for myxedema coma, which is a medical emergency requiring separate coding of any associated conditions.
Subclinical hypothyroidism and iodine-deficiency related presentations have their own E00-E02 categories; do not default them to E03.9 when specifically documented.
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About these codes
These ICD-10-CM codes are sourced from the official FY2026 tabular list published by the Centers for Medicare & Medicaid Services (CMS), effective April 1, 2026. Click any code for full clinical details including instructional notes, excludes guidance, and DRG mappings.
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