ICD-10 Code E03 – Other hypothyroidism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E03 – Other hypothyroidism
What it is
E03 identifies hypothyroidism that does not fit a more specific category. Use it for reduced thyroid function when the record supports hypothyroidism but does not name a distinct cause.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include fatigue, cold intolerance, weight gain, constipation, and slowed heart rate, but you should code only what is documented.
When to use this code
Use E03 when the clinician documents hypothyroidism and no more specific ICD-10 code is supported. It is appropriate for nonspecific or other forms of hypothyroidism, including cases where the cause is not stated. If the note identifies a specific etiology, choose that code instead.
Do not use for
Do not use E03 when the record supports congenital, postprocedural, or other specifically classified hypothyroidism. Check documentation if the provider names a more precise diagnosis or underlying condition.
Coding tip
Review the assessment and problem list carefully; if the cause is documented, code the more specific hypothyroidism category rather than E03.