ICD-10-CM 2027
ICD-10 code for myxedema
From the official ICD-10-CM alphabetic index entry “Myxedema (adult) (idiocy) (infantile) (juvenile)”. Page updated September 29, 2026.
About coding myxedema
The ICD-10-CM code for myxedema is E03.9 (Hypothyroidism, unspecified). The official index lists 8 more specific codes, 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 myxedema codes (official index)
- circumscribed E05.90 — Thyrotoxicosis, unspecified without thyrotoxic crisis or storm
- with storm E05.91 — Thyrotoxicosis, unspecified with thyrotoxic crisis or storm
- coma E03.5 — Myxedema coma
- congenital E00.1 — Congenital iodine-deficiency syndrome, myxedematous type
- cutis L98.5 — Mucinosis of the skin
- localized (pretibial) E05.90 — Thyrotoxicosis, unspecified without thyrotoxic crisis or storm
- with storm E05.91 — Thyrotoxicosis, unspecified with thyrotoxic crisis or storm
- papular L98.5 — Mucinosis of the skin
Common questions about myxedema ICD-10 codes
What is the ICD-10 code for myxedema?
- E03.9 — Hypothyroidism, unspecified. More specific codes apply when the documentation supports them: E05.90, E05.91, E03.5, E00.1 and others below.
What is the ICD-10 code for circumscribed myxedema?
- E05.90 — Thyrotoxicosis, unspecified without thyrotoxic crisis or storm.
What is the ICD-10 code for coma myxedema?
- E03.5 — Myxedema coma.
What is the ICD-10 code for congenital myxedema?
- E00.1 — Congenital iodine-deficiency syndrome, myxedematous type.
What is the ICD-10 code for cutis myxedema?
- L98.5 — Mucinosis of the skin.
What is the ICD-10 code for localized myxedema?
- E05.90 — Thyrotoxicosis, unspecified without thyrotoxic crisis or storm.
What is the ICD-10 code for papular myxedema?
- L98.5 — Mucinosis of the skin.
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.