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E66.811

E66.811Obesity, class 1

Billable / specific codeICD-10-CM

E66.811 is a billable, specific ICD-10-CM code for obesity, class 1. It is valid for submission on a claim.

Excludes2 inherited from the categories above E66.811

Also inherited, and the opposite of Excludes1: these conditions are not part of E66.811, but a patient can have both, so you may code both.

Written on E66 Overweight and obesity

  • adiposogenital dystrophy (E23.6)
  • lipomatosis dolorosa [Dercum] (E88.2)
  • lipomatosis NOS (E88.2)
  • Prader-Willi syndrome (Q87.11)

Other codes that can never be billed with E66.811

These codes carry an Excludes1 note pointing at E66.811. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading E66.811 alone.

  • R63.5Abnormal weight gain

Risk adjustment

E66.811 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

E66.811 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.

  • A57065Billing and Coding: Outpatient Psychiatry and Psychology Services
  • A57179Billing and Coding: Transesophageal Echocardiogram
  • A57736Billing and Coding: Vitamin D Assay Testing
  • A60204Billing and Coding: MolDX: Biomarker Testing for Risk Stratification in Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Dysfunction-Associated Steatohepatitis

How E66.811 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 E66.811.

  • Obesityclass1

The condition this code belongs to

Every code for the condition on one page, which one applies when, and the mistake coders make with it.

Code history

What changed, and when. Derived by diffing consecutive CMS release files — which matters when you are defending a code assigned under an earlier edition.

  • addedFY2024-FY2026

    Obesity, class 1

Related codes at this level

Codes that share E66.81. If E66.811 is not quite right, the correct code is usually one of these.

Questions about E66.811

Is E66.811 a billable ICD-10-CM code?
Yes. E66.811 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does E66.811 sit in the tabular list?
Endocrine, nutritional and metabolic diseases (E00-E89), in the block Overweight, obesity and other hyperalimentation (E65-E68).
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.