What is ICD-10 code E09.21?

E09.21 is the ICD-10-CM diagnosis code for Drug or chemical induced diabetes mellitus with diabetic nephropathy. It belongs to the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89). E09.21 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. E09.21 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. E09.21 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. E09.21 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.

Which HCC does E09.21 map to under V28?

E09.21 does not map to a CMS-HCC V28 payment category. Check the current CMS-HCC V28 model file for payment year 2026 rather than an older V24 tip sheet.

What does E09.21 pay in RAF?

E09.21 has no separately stated V28 community RAF weight. If it is not a V28 payment HCC, it adds nothing to a community RAF score.

What is the V28 vs V24 difference for E09.21?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. E09.21 was a payment HCC under V24 (Diabetes with Chronic Complications) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What documentation supports E09.21?

Always identify and document which specific drug or chemical caused the diabetes, as this information supports medical necessity and helps with adverse event tracking Ensure the nephropathy (kidney disease) is documented as present; if only diabetes without kidney involvement exists, use a different E09 code without the .21 designation Because E09.21 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM E09.21: Drug or chemical induced

E09.21 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC coding software

ICD-10-CM Code View

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Code lookupE09.21Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Diabetes mellitus (E08-E13)

E09.21

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Drug or chemical induced diabetes mellitus with diabetic nephropathy

This code describes diabetes that developed as a side effect of taking certain medications or being exposed to chemicals, and the patient has developed kidney damage as a complication. The kidney damage is a direct result of the diabetes caused by the drug or chemical exposure.

Buddy Insight

Drug or chemical induced diabetes mellitus with diabetic nephropathy indicates that a medication or chemical exposure has caused diabetes that has progressed to kidney damage.

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Mapped

HCC 18

Diabetes with Chronic Complic...

RAF 0.302

ACA/HHS

Mapped

HCC 20

HHS-HCC 20

Varies by metal level

ESRD/PACE

Mapped

HCC 18

Diabetes with Chronic Complic...

RAF 0.084

RXHCC

Mapped

HCC 30

Diabetes with Complications

RAF 0.495

Code Book Path

Official

E09Drug or chemical induced diabetes mellitus

E09.2Drug or chemical induced diabetes mellitus with kidney complications

E09.21Drug or chemical induced diabetes mellitus with diabetic nephropathy

Inclusion Terms

Official

Drug or chemical induced diabetes mellitus with intercapillary glomerulosclerosis
Drug or chemical induced diabetes mellitus with intracapillary glomerulonephrosis
Drug or chemical induced diabetes mellitus with Kimmelstiel-Wilson disease

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E09.21 in this effective period.

Related Child Codes

Official

E09.22Drug or chemical induced diabetes mellitus with diabetic chronic kidney disease

E09.29Drug or chemical induced diabetes mellitus with other diabetic kidney complication

Includes

Official

ICD-10-CM does not list Includes notes for E09.21 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for E09.21 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E09.21 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E09.21 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E09.21 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

The causative drug or chemical must be identified and coded separately.

Documentation must establish the presence of diabetic nephropathy with supporting evidence such as persistent proteinuria, microalbuminuria, or abnormal creatinine.

The causal chain from drug exposure to diabetes to kidney damage should be clear.

If chronic kidney disease staging is also present, use E09.22 instead.

MEAT Support

HCC Buddy guidance

The causative drug or chemical must be identified and coded separately.

Documentation must establish the presence of diabetic nephropathy with supporting evidence such as persistent proteinuria, microalbuminuria, or abnormal creatinine.

The causal chain from drug exposure to diabetes to kidney damage should be clear.

If chronic kidney disease staging is also present, use E09.22 instead.

Audit Caution

HCC Buddy guidance

Do not assign this code simultaneously with E09.22, as nephropathy and CKD represent overlapping but distinct concepts in the coding system.

Ensure the kidney disease is attributable to diabetes rather than to other causes such as hypertension alone.

The causative drug must be identified to justify the E09 category over E11.

Common Mistakes

HCC Buddy guidance

E09.22 (with diabetic chronic kidney disease) is preferred when CKD staging is documented.

E09.29 (other diabetic kidney complication) applies for renal manifestations that are not nephropathy or CKD.

E11.21 (Type 2 with nephropathy) should not be used when diabetes is drug-induced.

N18 codes may be needed as additional codes for CKD staging.

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is E09.21 an HCC code?

Yes. E09.21 maps to Diabetes with Chronic Complications under the V24 model but is not retained in V28.

Code: E09.21
Description: Drug or chemical induced diabetes mellitus with diabetic nephropathy
HCC (V28): No CMS-HCC V28 mapping
RAF: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

V24HCC 18, Diabetes with Chronic Complications

0.302

ESRDHCC 18, Diabetes with Chronic Complications

0.084

RxHCCHCC 30, Diabetes with Complications

0.495

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work E09.21 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E09.21

For E09.21 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E09.21 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

E09.21 is the ICD-10-CM diagnosis code for drug or chemical induced diabetes mellitus with diabetic nephropathy. This code describes diabetes that developed as a side effect of taking certain medications or being exposed to chemicals, and the patient has developed kidney damage as a complication. The kidney damage is a direct result of the diabetes caused by the drug or chemical exposure. E09.21 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering diabetes mellitus (e08-e13).

Under the older CMS-HCC V24 model, E09.21 maps to Diabetes with Chronic Complications (HCC 18) with a community, non-dual, aged base RAF weight of 0.302. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Always identify and document which specific drug or chemical caused the diabetes, as this information supports medical necessity and helps with adverse event tracking. Because E09.21 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E09.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Always identify and document which specific drug or chemical caused the diabetes, as this information supports medical necessity and helps with adverse event tracking
•Ensure the nephropathy (kidney disease) is documented as present; if only diabetes without kidney involvement exists, use a different E09 code without the .21 designation

Clinical Significance

Drug or chemical induced diabetes mellitus with diabetic nephropathy indicates that a medication or chemical exposure has caused diabetes that has progressed to kidney damage. Diabetic nephropathy is characterized by persistent albuminuria and progressive decline in glomerular filtration rate. This represents a significant chronic complication requiring nephroprotective strategies including blood pressure control, glycemic optimization, and potentially ACE inhibitor or ARB therapy.

Documentation Requirements

✓The causative drug or chemical must be identified and coded separately.
✓Documentation must establish the presence of diabetic nephropathy with supporting evidence such as persistent proteinuria, microalbuminuria, or abnormal creatinine.
✓The causal chain from drug exposure to diabetes to kidney damage should be clear.
✓If chronic kidney disease staging is also present, use E09.22 instead.

Commonly Confused Codes

•E09.22 (with diabetic chronic kidney disease) is preferred when CKD staging is documented.
•E09.29 (other diabetic kidney complication) applies for renal manifestations that are not nephropathy or CKD.
•E11.21 (Type 2 with nephropathy) should not be used when diabetes is drug-induced.
•N18 codes may be needed as additional codes for CKD staging.