Question 1

What is ICD-10 code E88.819?

Accepted Answer

E88.819 is the ICD-10-CM diagnosis code for insulin resistance, unspecified. Insulin resistance of an unspecified type, where the body's cells don't respond properly to insulin but the specific classification is not determined. E88.819 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).

E88.819 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This is an unspecified code; use only when the type of insulin resistance cannot be determined or specified.

Question 2

Is E88.819 an HCC code?

Accepted Answer

No. E88.819 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is E88.819 billable?

Accepted Answer

Yes. E88.819 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. E88.819 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

What is the V28 vs V24 difference for E88.819?

Accepted Answer

E88.819 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards E88.819 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting E88.819?

Accepted Answer

This is an unspecified code; use only when the type of insulin resistance cannot be determined or specified Attempt to determine if Type A or other specific insulin resistance applies before using this code

HCC Buddy Code Card

E88.819

Is E88.819 an HCC code?

Get the V28 RAF + MEAT cheat sheet

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

Work E88.819 in HCC Buddy

E88.819 ICD-10-CM Code: Insulin resistance, unspecified

HCC Buddy Code Card

E88.819

Is E88.819 an HCC code?

Get the V28 RAF + MEAT cheat sheet

What This Code Means

Coding Tips

Child Codes

Code Hierarchy

Work E88.819 in HCC Buddy