What is ICD-10 code D70.1?

D70.1 is the ICD-10-CM diagnosis code for Agranulocytosis secondary to cancer chemotherapy. A dangerous drop in white blood cells caused by cancer chemotherapy treatment that kills bone marrow cells. D70.1 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. D70.1 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. D70.1 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. D70.1 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.

What is the V28 vs V24 difference for D70.1?

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. D70.1 was a payment HCC under V24 (Disorders of Immunity) 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 should coders know when reporting D70.1?

Always link this code to the underlying cancer diagnosis and the specific chemotherapy regimen when documented This is a known adverse effect; ensure the chemotherapy treatment is documented in the medical record Because D70.1 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.

2026 ICD-10-CM D70.1: Agranulocytosis secondary

ICD-10-CM Code View

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Code lookupD70.1Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) / Other disorders of blood and blood-forming organs (D70-D77)

D70.1

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

Agranulocytosis secondary to cancer chemotherapy

A dangerous drop in white blood cells caused by cancer chemotherapy treatment that kills bone marrow cells.

Buddy Insight

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Mapped

HCC 47

Disorders of Immunity

RAF 0.665

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

Mapped

HCC 47

Disorders of Immunity

RAF 0.078

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

D70Neutropenia

D70.1Agranulocytosis secondary to cancer chemotherapy

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for D70.1 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for D70.1 in this effective period.

Related Child Codes

Official

D70.0Congenital agranulocytosis

D70.2Other drug-induced agranulocytosis

D70.3Neutropenia due to infection

D70.4Cyclic neutropenia

D70.8Other neutropenia

Includes

Official

agranulocytosis
decreased absolute neurophile count (ANC)

Excludes 1

Official

neutropenic splenomegaly (D73.81)
transient neonatal neutropenia (P61.5)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D70.1 in this effective period.

Use Additional

Official

code for adverse effect, if applicable, to identify drug (T45.1X5)

Code Also

Official

underlying neoplasm

Buddy Documentation Tip

HCC Buddy guidance

Document the specific chemotherapy regimen causing agranulocytosis, nadir absolute neutrophil count, timing relative to chemotherapy cycle, and whether febrile neutropenia developed.

Record G-CSF prophylaxis or treatment, any infectious complications, and the impact on subsequent chemotherapy dosing or scheduling.

MEAT Support

HCC Buddy guidance

Document the specific chemotherapy regimen causing agranulocytosis, nadir absolute neutrophil count, timing relative to chemotherapy cycle, and whether febrile neutropenia developed.

Record G-CSF prophylaxis or treatment, any infectious complications, and the impact on subsequent chemotherapy dosing or scheduling.

Audit Caution

HCC Buddy guidance

Code the underlying malignancy first, then D70.1, followed by the adverse effect T-code for the specific chemotherapy agent.

Do not assign D70.1 for pre-existing neutropenia in a cancer patient if unrelated to chemotherapy.

This code is for the chemotherapy-induced effect specifically — radiation-induced neutropenia is coded differently.

Common Mistakes

HCC Buddy guidance

D70.2 (Other drug-induced agranulocytosis) — for non-chemotherapy medications

D70.0 (Congenital agranulocytosis) — inherited rather than treatment-related

D70.9 (Neutropenia, unspecified) — should specify the chemotherapy-related cause

D61.1 (Drug-induced aplastic anemia) — pancytopenia beyond isolated neutropenia.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is D70.1 an HCC code?

Yes. D70.1 maps to Disorders of Immunity under the V24 model but is not retained in V28.

Code: D70.1
Description: Agranulocytosis secondary to cancer chemotherapy
HCC (V28): No CMS-HCC V28 mapping
RAF: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

V24HCC 47, Disorders of Immunity

0.665

ESRDHCC 47, Disorders of Immunity

0.078

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 D70.1 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for D70.1

For D70.1to 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 D70.1 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

D70.1 is the ICD-10-CM diagnosis code for agranulocytosis secondary to cancer chemotherapy. A dangerous drop in white blood cells caused by cancer chemotherapy treatment that kills bone marrow cells. D70.1 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering other disorders of blood and blood-forming organs (d70-d77).

Under the older CMS-HCC V24 model, D70.1 maps to Disorders of Immunity (HCC 47) with a community, non-dual, aged base RAF weight of 0.665. 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 link this code to the underlying cancer diagnosis and the specific chemotherapy regimen when documented. Because D70.1 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 D70.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Always link this code to the underlying cancer diagnosis and the specific chemotherapy regimen when documented
•This is a known adverse effect; ensure the chemotherapy treatment is documented in the medical record

Clinical Significance

Agranulocytosis secondary to cancer chemotherapy is a common and expected complication of cytotoxic treatment, characterized by severely reduced neutrophil counts that increase the risk of life-threatening infections. The severity and duration depend on the specific chemotherapy regimen, and management includes prophylactic or therapeutic G-CSF, infection surveillance, and sometimes hospitalization for febrile neutropenia.

Documentation Requirements

✓Document the specific chemotherapy regimen causing agranulocytosis, nadir absolute neutrophil count, timing relative to chemotherapy cycle, and whether febrile neutropenia developed.
✓Record G-CSF prophylaxis or treatment, any infectious complications, and the impact on subsequent chemotherapy dosing or scheduling.

Use Additional Code

code for adverse effect, if applicable, to identify drug (T45.1X5)

Code Also

underlying neoplasm

Commonly Confused Codes

•D70.2 (Other drug-induced agranulocytosis): for non-chemotherapy medications
•D70.0 (Congenital agranulocytosis): inherited rather than treatment-related
•D70.9 (Neutropenia, unspecified): should specify the chemotherapy-related cause
•D61.1 (Drug-induced aplastic anemia): pancytopenia beyond isolated neutropenia.