FY2027 ICD-10-CM reference
E66: Overweight and obesity
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Overweight and obesity. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
More specific FY2027 codes
- E66.0: Obesity due to excess caloriesNonbillable heading
- E66.1: Drug-induced obesityBillable code
- E66.2: Morbid (severe) obesity with alveolar hypoventilationBillable code
- E66.3: OverweightBillable code
- E66.8: Other obesityNonbillable heading
- E66.9: Obesity, unspecifiedBillable code
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.
Source: E00-E89 (chapter, inherited).
Excludes1
transitory endocrine and metabolic disorders specific to newborn (P70-P74)
Source: E00-E89 (chapter, inherited).
Code first
obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-)
Source: E66 (category, direct).
Instructional note
code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)
Source: E66 (category, direct).
Excludes2
adiposogenital dystrophy (E23.6)
Source: E66 (category, direct).
Excludes2
lipomatosis dolorosa [Dercum] (E88.2)
Source: E66 (category, direct).
Excludes2
lipomatosis NOS (E88.2)
Source: E66 (category, direct).
Excludes2
Prader-Willi syndrome (Q87.11)
Source: E66 (category, direct).
Compare the FY2027 additions, removals and billable-status changes
What does E66 mean in FY2027?
The official ICD-10-CM descriptor is Overweight and obesity. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is E66 billable in FY2027?
The FY2027 order file marks E66 as a nonbillable heading. Select a complete billable child code.
Does E66 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition