Question 1

What is ICD-10 code E66.89?

Accepted Answer

E66.89 is the ICD-10-CM diagnosis code for other obesity not elsewhere classified. A category for obesity that doesn't fit into other specific obesity classifications, used when the type of obesity is documented but not elsewhere classified. E66.89 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering overweight, obesity and other hyperalimentation (e65-e68).

E66.89 is a billable ICD-10-CM code, but the current payload does not show a mapping under the CMS-HCC V28 or V24 community payment models, and none under the ESRD, Part D RxHCC, or HHS-HCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.

Use this code only when obesity is documented but doesn't meet criteria for other E66 subcategories.

Question 2

Is E66.89 an HCC code?

Accepted Answer

E66.89 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

Question 3

Is E66.89 billable?

Accepted Answer

Yes. E66.89 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. E66.89 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

Which HCC does E66.89 map to under V28?

Accepted Answer

E66.89 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

Question 5

What RAF reference is published for E66.89?

Accepted Answer

E66.89 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

Question 6

What is the V28 vs V24 difference for E66.89?

Accepted Answer

E66.89 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

Question 7

What documentation supports E66.89?

Accepted Answer

Use this code only when obesity is documented but doesn't meet criteria for other E66 subcategories Always check if a more specific obesity code (E66.0-E66.3) applies before assigning this code E66.89 is not a CMS-HCC V28 payment code in the verified current source, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

Question 8

Can E66.89 be a primary diagnosis?

Accepted Answer

Usually yes, when it is the condition chiefly responsible for the encounter and the note supports it. The exception is in the code-first instruction: when obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-) is documented, that condition is sequenced first and E66.89 follows it. For risk adjustment the order does not matter; the V28 category is the same either way.

Question 9

Which codes cannot be reported with E66.89?

Accepted Answer

The Excludes1 note that applies to E66.89 lists transitory endocrine and metabolic disorders specific to newborn (P70-P74). An Excludes1 condition is not reported together with E66.89; report one or the other, unless the two conditions are unrelated, which the ICD-10-CM Official Guidelines (Section I.A.12.a) allow. The Excludes2 note lists adiposogenital dystrophy (E23.6); lipomatosis dolorosa [Dercum] (E88.2); lipomatosis NOS (E88.2); Prader-Willi syndrome (Q87.11); those are separate conditions that may be reported together with E66.89 when both are documented.

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E66.89 ICD-10-CM Code: Other obesity not elsewhere classified

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E66.89

Is E66.89 an HCC code?

Get the V28 mapping + MEAT cheat sheet

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

E66.89 code history

Also searched as

More on E66.89

Code family

Related condition guides

Referenced in blog posts

Work E66.89 in HCC Buddy