Billable / Specific Code
ICD-10-CM E66.01 is the diagnosis code for Morbid (severe) obesity due to excess calories. This code falls under the section "Overweight, obesity and other hyperalimentation" within Chapter 4 — Endocrine, nutritional and metabolic diseases (E00-E89). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as E66.01. They are mutually exclusive:
Understanding where E66.01 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, E66.01 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
E66.01 is the ICD-10-CM diagnosis code for "Morbid (severe) obesity due to excess calories". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of E66.01 is E66.0 ("Obesity due to excess calories"). E66.01 provides a more specific classification within this category.
E66.01 is located in Section E65-E68 — "Overweight, obesity and other hyperalimentation" within Chapter 4 of the ICD-10-CM Tabular List.
Use E66.01 when the patients documented diagnosis matches "Morbid (severe) obesity due to excess calories" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Morbid (severe) obesity due to excess calories is E66.01.
Yes, E66.01 can be used as a primary diagnosis code since it is billable and specific.
E66.01 is in Chapter 4 of the ICD-10-CM Tabular List.
Type 1 Excludes for E66.01 include: morbid (severe) obesity with alveolar hypoventilation (E66.2).
Yes, E66.01 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.