E66.01 – Morbid (severe) obesity due to excess calories

ICD-10-CM 2027 diagnosis code · Overweight, obesity and other hyperalimentation

Billable code

ICD-10-CM code E66.01
Code
E66.01 (claims format: E6601)
Description
Morbid (severe) obesity due to excess calories
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
4. Endocrine, nutritional and metabolic diseases (E00-E89)
Block
E65-E68 Overweight, obesity and other hyperalimentation
Parent codes
E66 › E66.0

Notes for E66.01

Excludes1 (not coded here):
  • morbid (severe) obesity with alveolar hypoventilation (E66.2)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

E66 – Overweight and obesity

Excludes2 (not included here):
  • adiposogenital dystrophy (E23.6)
  • lipomatosis dolorosa [Dercum] (E88.2)
  • lipomatosis NOS (E88.2)
  • Prader-Willi syndrome (Q87.11)
Code first:
  • obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-)
Use additional code:
  • code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)

Index terms for E66.01

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in E66.0

Frequently asked questions

What is ICD-10 code E66.01?

E66.01 is the ICD-10-CM code for morbid (severe) obesity due to excess calories, in the block E65-E68 (Overweight, obesity and other hyperalimentation).

Is E66.01 a billable code?

Yes. E66.01 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does E66.01 belong to?

It belongs to category E66 – Overweight and obesity.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.