ICD-10 Code for hypothyroidism

The ICD-10-CM code for hypothyroidism is E03.9 when documented without further specification. Unspecified hypothyroidism is E03.9; autoimmune (Hashimoto's) and post-surgical causes have their own codes.

Which Code Should You Use?

E03.9 — Hypothyroidism, unspecified

Hypothyroidism documented without a specified cause.

E06.3 — Autoimmune thyroiditis

Hashimoto's (autoimmune) thyroiditis documented.

E89.0 — Postprocedural hypothyroidism

Postprocedural hypothyroidism (after thyroidectomy or radioablation).

E02 — Subclinical iodine-deficiency hypothyroidism

Subclinical iodine-deficiency hypothyroidism.

What to Document

  • Cause when known (autoimmune, post-surgical, drug-induced E03.2).
  • Long-term levothyroxine therapy (no Z79 analog - the condition code suffices).
  • Pregnancy context (O99.28- applies as the first-listed code).

Coding Notes

"Hypothyroidism" alone indexes to E03.9. Myxedema coma is the higher-acuity E03.5.

References

Reviewed by Prajwal Shrestha, CPC, CRC
Certified Professional Coder (CPC) and Certified Risk Adjustment Coder (CRC) · AAPC Member ID 01997614 · About · Editorial policy · Content last reviewed: 2025-10-01

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