ICD-10-CM category E66
Overweight and obesity: every E66 code with its CMS-HCC V28 status
E66, Overweight and obesity, holds 14 codes in the FY2026 ICD-10-CM set: 10 billable codes and 4 header codes that need a further character. 3 of them maps to a CMS-HCC V28 payment category (HCC 48) for payment year 2026. The other 7 billable codes carry no V28 HCC and do not risk-adjust.
CMS-HCC V28 categories in E66 (1)
Coefficients are the code-level reference values from the CMS V28 factor file (community, non-dual, aged), not a member's score. Hierarchy, interactions, and enrollment segment decide what a documented condition contributes.
All 14 E66 codes (FY2026)
Descriptors are the FY2026 order-file text. Header codes need a further character and cannot be reported; open any billable code for its tabular notes, MEAT guidance, and mapping detail.
| Code | Description | FY2026 | CMS-HCC V28 |
|---|---|---|---|
| E66 | Overweight and obesity | Header | Header code, not reportable |
| E66.0 | Obesity due to excess calories | Header | Header code, not reportable |
| E66.01 | Morbid (severe) obesity due to excess calories | Billable | HCC 48 |
| E66.09 | Other obesity due to excess calories | Billable | No V28 HCC |
| E66.1 | Drug-induced obesity | Billable | No V28 HCC |
| E66.2 | Morbid (severe) obesity with alveolar hypoventilation | Billable | HCC 48 |
| E66.3 | Overweight | Billable | No V28 HCC |
| E66.8 | Other obesity | Header | Header code, not reportable |
| E66.81 | Obesity class | Header | Header code, not reportable |
| E66.811 | Obesity, class 1 | Billable | No V28 HCC |
| E66.812 | Obesity, class 2 | Billable | No V28 HCC |
| E66.813 | Obesity, class 3 | Billable | HCC 48 |
| E66.89 | Other obesity not elsewhere classified | Billable | No V28 HCC |
| E66.9 | Obesity, unspecified | Billable | No V28 HCC |
Documentation guides for E66
Frequently asked questions
How many E66 codes are there?
The E66 category (Overweight and obesity) has 14 codes in the FY2026 ICD-10-CM order file: 10 billable and 4 header codes, counting the category itself. Only a billable code can be reported on a claim.
Which E66 codes map to an HCC under CMS-HCC V28?
3 billable codes in E66 map to HCC 48 in the CMS-HCC V28 model for payment year 2026. HCC 48 (Morbid Obesity) carries the most, with 3 codes. The 7 billable codes without a V28 category are marked "No V28 HCC" in the table.
Which E66 codes are not billable?
E66 itself and 3 subcategory codes are header codes that need a further character before they can be reported: E66.0 (Obesity due to excess calories), E66.8 (Other obesity), E66.81 (Obesity class). Each one is listed in the table with the billable codes beneath it.
Source: FY2026 ICD-10-CM order file (FY 2026 Apr update) for codes, billability, and descriptors; CMS-HCC V28 PY2026 final ICD-10-CM mappings and relative factors for payment status. Table generated 2026-09-10.