What is ICD-10 code C88.80?

C88.80 is the ICD-10-CM diagnosis code for Other malignant immunoproliferative diseases not having achieved remission. Other rare blood or lymphoid cancers involving abnormal immune cell proliferation that have not responded adequately to treatment. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C88.80 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C88.80 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. C88.80 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. C88.80 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 C88.80?

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. For C88.80, V28 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors at RAF 0.545 while V24 mapped to Lymphoma and Other Cancers at RAF 0.675. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting C88.80?

This is a catch-all code; use only when a more specific immunoproliferative disease code does not apply Provide detailed clinical documentation of the specific disease entity in the medical record for clarity Because C88.80 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.

C88.80 ICD-10 Code: Other malignant

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupC88.80Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)

C88.80

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

Other malignant immunoproliferative diseases not having achieved remission

Other rare blood or lymphoid cancers involving abnormal immune cell proliferation that have not responded adequately to treatment.

Buddy Insight

CMS-HCC V28

Mapped

HCC 21

Breast, Prostate, Colorectal ...

RAF 0.545

CMS-HCC V24

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.675

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

RAF 0.0

RXHCC

Mapped

HCC 21

Hodgkin Lymphoma and Other Ca...

RAF 0.0

Code Trumping

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Code Book Path

Official

C88Malignant immunoproliferative diseases and certain other B-cell lymphomas

C88.8Other malignant immunoproliferative diseases

C88.80Other malignant immunoproliferative diseases not having achieved remission

Inclusion Terms

Official

Other malignant immunoproliferative diseases NOS
Other malignant immunoproliferative diseases with failed remission

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C88.80 in this effective period.

Related Child Codes

Official

C88.81Other malignant immunoproliferative diseases, in remission

Includes

Official

ICD-10-CM does not list Includes notes for C88.80 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for C88.80 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C88.80 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C88.80 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C88.80 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must clearly describe the specific immunoproliferative entity with pathology and immunohistochemistry supporting the diagnosis.

Laboratory studies including serum protein electrophoresis and immunofixation should be documented.

Justification for why a more specific code does not apply, treatment regimen, and non-remission status must be recorded.

MEAT Support

HCC Buddy guidance

Documentation must clearly describe the specific immunoproliferative entity with pathology and immunohistochemistry supporting the diagnosis.

Laboratory studies including serum protein electrophoresis and immunofixation should be documented.

Justification for why a more specific code does not apply, treatment regimen, and non-remission status must be recorded.

Audit Caution

HCC Buddy guidance

This is a residual category that should only be used after excluding all more specific immunoproliferative disease codes.

Provide detailed clinical documentation to justify this code selection during audits.

Ensure the condition truly represents a malignant immunoproliferative process rather than a benign or reactive immunoproliferative condition.

Common Mistakes

HCC Buddy guidance

C88.81 (other malignant immunoproliferative diseases in remission) requires documented remission.

C88.00-C88.41 provide more specific codes for defined entities like Waldenstrom macroglobulinemia, heavy chain disease, IPSID, and MALT lymphoma.

C88.90 (malignant immunoproliferative disease, unspecified) is even less specific and should be avoided when possible.

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 C88.80 an HCC code?

Yes. C88.80 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model (and Lymphoma and Other Cancers under V24).

HCC Category Mapping

V28HCC 21, Breast, Prostate, Colorectal and Other Cancers and Tumors

0.545

V24HCC 10, Lymphoma and Other Cancers

0.675

ESRDHCC 10, Lymphoma and Other Cancers

0.000

RxHCCHCC 21, Hodgkin Lymphoma and Other Cancers

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

MEAT Criteria for C88.80

For C88.80to 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 C88.80 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

C88.80 is the ICD-10-CM diagnosis code for other malignant immunoproliferative diseases not having achieved remission. Other rare blood or lymphoid cancers involving abnormal immune cell proliferation that have not responded adequately to treatment. C88.80 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).

Under the CMS-HCC V28 risk adjustment model, C88.80 maps to Breast, Prostate, Colorectal and Other Cancers and Tumors (HCC 21) with a community, non-dual, aged base RAF weight of 0.545. Under the older CMS-HCC V24 model, C88.80 maps to Lymphoma and Other Cancers (HCC 10) with a community, non-dual, aged base RAF weight of 0.675. 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.

This is a catch-all code; use only when a more specific immunoproliferative disease code does not apply. Because C88.80 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 C88.80 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This is a catch-all code; use only when a more specific immunoproliferative disease code does not apply
•Provide detailed clinical documentation of the specific disease entity in the medical record for clarity

Clinical Significance

Other malignant immunoproliferative diseases not having achieved remission is a residual category for rare immunoproliferative neoplasms that do not fit into more specific subcategories such as Waldenstrom macroglobulinemia, heavy chain disease, or MALT lymphoma. These conditions involve pathologic proliferation of immune cells producing abnormal proteins and may include rare variants of lymphoplasmacytic disorders. Non-remission status indicates ongoing active disease.

Documentation Requirements

✓Documentation must clearly describe the specific immunoproliferative entity with pathology and immunohistochemistry supporting the diagnosis.
✓Laboratory studies including serum protein electrophoresis and immunofixation should be documented.
✓Justification for why a more specific code does not apply, treatment regimen, and non-remission status must be recorded.

Commonly Confused Codes

•C88.81 (other malignant immunoproliferative diseases in remission) requires documented remission.
•C88.00-C88.41 provide more specific codes for defined entities like Waldenstrom macroglobulinemia, heavy chain disease, IPSID, and MALT lymphoma.
•C88.90 (malignant immunoproliferative disease, unspecified) is even less specific and should be avoided when possible.