Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0 (FY2026), Appendix B.

MS-DRG 640 — MISCELLANEOUS DISORDERS OF NUTRITION, METABOLISM, FLUIDS AND ELECTROLYTES WITH MCC (MDC 10)
MS-DRG 641 — MISCELLANEOUS DISORDERS OF NUTRITION, METABOLISM, FLUIDS AND ELECTROLYTES WITHOUT MCC (MDC 10)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

Other models: CMS-HCC V22 HCC 22

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Morbid (severe) obesity due to excess calories is a billable ICD-10-CM diagnosis code (E66.01).

Sequencing, inclusion, and exclusion notes published for E66.01 in the official ICD-10-CM tabular list.

Conditions that can never be reported with this code; the two are mutually exclusive.

Conditions not covered by this code, but which may be reported alongside it when both are present.

Underlying conditions that must be sequenced before this code.

obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-)

Supplementary codes the tabular list directs you to add.

Use additional code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)

Official ICD-10-CM classifications closest to E66.01 in its code family, with their registry titles.

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.