Diabetes Mellitus (Type 2) HCC Coding Guide
Complete HCC coding guide for Type 2 Diabetes Mellitus (E11.x) including ICD-10 to HCC mapping, V28 RAF weights, documentation tips, and common coding mistakes.
Quick Facts
HCC Categories
HCC 37 — Diabetes with Chronic Complications
HCC 38 — Diabetes with Glycemic, Unspecified, or No Complications
RAF Weight Range
0.105 – 0.302
Community, non-dual, aged (V28)
Model
CMS-HCC V28 (PY2026 — 100% phase-in)
10 ICD-10 codes map to payment HCCs
Overview
Type 2 diabetes mellitus is one of the highest-impact conditions in HCC risk adjustment, affecting over 37 million Americans. Under the CMS-HCC V28 model, diabetes codes are stratified by complication severity — uncomplicated diabetes, diabetes with complications, and diabetes with acute complications each map to different HCC categories with progressively higher RAF weights. Accurate coding requires documenting the specific type of diabetes, current complications, and treatment plan. Medical coders must capture the causal relationship between diabetes and its manifestations using combination codes from the E11 category to ensure proper HCC mapping and RAF score calculation.
ICD-10 to HCC Mapping
| ICD-10 Code | Description | Billable | HCC Mapping |
|---|---|---|---|
| E11.9 | Type 2 diabetes mellitus without complications | Yes | HCC 38 |
| E11.65 | Type 2 diabetes mellitus with hyperglycemia | Yes | HCC 38 |
| E11.22 | Type 2 diabetes mellitus with diabetic chronic kidney disease | Yes | HCC 37 |
| E11.40 | Type 2 diabetes mellitus with diabetic neuropathy, unspecified | Yes | HCC 37 |
| E11.311 | Type 2 diabetes mellitus with unspecified diabetic retinopathy with macular edema | Yes | HCC 37 |
| E11.51 | Type 2 diabetes mellitus with diabetic peripheral angiopathy without gangrene | Yes | HCC 37 |
| E11.621 | Type 2 diabetes mellitus with foot ulcer | Yes | HCC 37 |
| E11.69 | Type 2 diabetes mellitus with other specified complication | Yes | HCC 37 |
| E11.21 | Type 2 diabetes mellitus with diabetic nephropathy | Yes | HCC 37 |
| E11.42 | Type 2 diabetes mellitus with diabetic polyneuropathy | Yes | HCC 37 |
RAF weights are community, non-dual, aged base coefficients from the CMS-HCC V28 model (PY2026). Verify against the latest CMS rate announcement for payment calculations.
Documentation Tips
Always document the specific type of diabetes (Type 1, Type 2, or secondary) — never code 'unspecified diabetes' when the type is known.
Document causal relationships between diabetes and complications (e.g., 'diabetic nephropathy' vs. 'nephropathy in a patient with diabetes').
Use combination codes from E11 for diabetes with complications rather than coding diabetes and complications separately.
Specify laterality for diabetic retinopathy and severity of macular edema when applicable.
Document current HbA1c level and whether hyperglycemia or hypoglycemia is present at the encounter.
Record all active diabetic complications at every encounter — do not rely on problem list carry-forward without provider attestation.
Document the treatment plan including medications, insulin use, and monitoring frequency to satisfy MEAT criteria.
Common Coding Mistakes
Coding E11.9 (without complications) when the patient has documented diabetic complications — always code to the highest specificity.
Failing to link diabetes as the cause of kidney disease, neuropathy, or retinopathy when the provider has documented the causal relationship.
Using unspecified diabetes codes (E13.x) instead of Type 2 (E11.x) when the type is clearly documented.
Missing the opportunity to code diabetic chronic kidney disease (E11.22) alongside the specific CKD stage code.
Not capturing hyperglycemia (E11.65) when the encounter note documents elevated blood glucose or uncontrolled diabetes.
V24 to V28 Changes
V28 consolidated the diabetes HCC hierarchy from three V24 categories (HCC 17, 18, 19) into two: HCC 37 (Diabetes with Chronic Complications) and HCC 38 (Diabetes with Glycemic, Unspecified, or No Complications). The former V24 HCC 19 for acute complications was merged into HCC 37. RAF weights were recalibrated — uncomplicated diabetes carries a lower weight under V28, emphasizing the importance of capturing and documenting all diabetic complications.
Related Conditions
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