ICD-10 Code for Obesity
The ICD-10-CM code for obesity is E66.9 — Obesity, unspecified. This is the code the Alphabetic Index gives for obesity with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
E66.9 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which obesity code should you use?
The Alphabetic Index lists 16 codes under Obesity. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| with alveolar hypoventilation | E66.2 | Morbid (severe) obesity with alveolar hypoventilation | |
| adrenal | E27.8 | Other specified disorders of adrenal gland | |
| constitutional | E66.89 | Other obesity not elsewhere classified | |
| dietary counseling and surveillance | Z71.3 | Dietary counseling and surveillance | |
| drug-induced | E66.1 | Drug-induced obesity | |
| endocrine | E66.89 | Other obesity not elsewhere classified | |
| endogenous | E66.89 | Other obesity not elsewhere classified | |
| exogenous | E66.09 | Other obesity due to excess calories | |
| familial | E66.89 | Other obesity not elsewhere classified | |
| glandular | E66.89 | Other obesity not elsewhere classified | |
| hypoventilation syndrome | E66.2 | Morbid (severe) obesity with alveolar hypoventilation | |
| morbid | E66.01 | Morbid (severe) obesity due to excess calories | |
| nutritional | E66.09 | Other obesity due to excess calories | |
| pituitary | E23.6 | Other disorders of pituitary gland | |
| severe | E66.01 | Morbid (severe) obesity due to excess calories | |
| specified type NEC | E66.89 | Other obesity not elsewhere classified |
Obesity complicating
Obesity due to
| disruption of MC4R pathway | E88.82 | Obesity due to disruption of MC4R pathway | |
| drug | E66.1 | Drug-induced obesity | |
| excess calories | E66.09 | Other obesity due to excess calories | |
| excess calories › morbid | E66.01 | Morbid (severe) obesity due to excess calories | |
| excess calories › severe | E66.01 | Morbid (severe) obesity due to excess calories | |
| gene mutation › leptin | E88.82 | Obesity due to disruption of MC4R pathway | |
| gene mutation › leptin receptor | E88.82 | Obesity due to disruption of MC4R pathway | |
| gene mutation › melanocortin 4 Receptor | E88.82 | Obesity due to disruption of MC4R pathway | |
| gene mutation › nuclear receptor coactivator 1 | E88.82 | Obesity due to disruption of MC4R pathway | |
| gene mutation › proopiomelanocortin | E88.82 | Obesity due to disruption of MC4R pathway | |
| gene mutation › proprotein convertase subtilisin/kexin type 1 | E88.82 | Obesity due to disruption of MC4R pathway | |
| gene mutation › src homology 2B adaptor signaling protein | E88.82 | Obesity due to disruption of MC4R pathway |
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources