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E03.5

E03.5Myxedema coma

Billable / specific codeICD-10-CM

E03.5 is a billable, specific ICD-10-CM code for myxedema coma. It is valid for submission on a claim.

Risk adjustment

E03.5 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 202 Coma, Brain Compression/Anoxic Damage0.543 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

E03.5 is named in 11 Medicare coverage policies 11 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56612Billing and Coding: CT of the Head
  • A56645Billing and Coding: Controlled Substance Monitoring and Drugs of Abuse Testing
  • A56773Billing and Coding: Neurophysiology Evoked Potentials (NEPs)
  • A56781Billing and Coding: Transthoracic Echocardiography (TTE)

How E03.5 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to E03.5.

  • Comamyxedematous
  • Myxedemacoma

Related codes at this level

Codes that share E03. If E03.5 is not quite right, the correct code is usually one of these.

Questions about E03.5

Is E03.5 a billable ICD-10-CM code?
Yes. E03.5 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does E03.5 sit in the tabular list?
Endocrine, nutritional and metabolic diseases (E00-E89), in the block Disorders of thyroid gland (E00-E07).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.