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V28 HCC 18

Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid

Under the CMS-HCC V28 risk adjustment model (PY2026 Medicare Advantage), HCC 18 has a source-labeled community non-dual aged reference coefficient of 2.341, and 26 ICD-10-CM diagnosis codes appear in its official mapping. In the V28 hierarchy it is superseded by HCC 17 when a more severe category in the same disease group is also present.

By the HCC Buddy Coding Team · Reviewed: May 30, 2026
V28 HCC 18Community non-dual aged reference coefficient 2.341
See ICD-10-CM codes for HCC 18Open the RAF Calculator

RAF factors

The community factor varies by Medicaid and originally-disabled status; the institutional factor applies to long-term-institutional members. These are the CMS-HCC V28 PY2026 relative factors.

Community NA: 2.341Community PBA: 2.166Community FBA: 2.277Community ND: 2.486Community PBD: 2.403Community FBD: 2.537Institutional: 1.11

These are source-labeled code-level HCC coefficient references, not a full member score. Use the RAF Calculator with complete member context for CMS-HCC V28 PY2026. No score is shown unless every required source and calculation check passes.

V28 hierarchy

Trumped by: HCC 17 (a more severe category in the same disease group supersedes this one).

Supersedes: HCC 19, HCC 20, HCC 21, HCC 22, HCC 23 (this category is counted instead of these when they co-occur).

ICD-10-CM codes that map to HCC 18 (26)

ICD-10-CM codes in the official mapping for this category under CMS-HCC V28 PY2026. Open any code for its full description and coding guidance.

Coder workflow notes

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Frequently asked questions

What is CMS-HCC V28 category 18?

HCC 18 is "Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid", a Hierarchical Condition Category in the CMS-HCC V28 risk adjustment model (100% phase-in for payment year 2026). 26 ICD-10-CM codes appear in its official mapping.

What reference coefficient is published for HCC 18?

The source-labeled community non-dual aged reference coefficient for CMS-HCC V28 category 18 is 2.341. The exact coefficient varies by enrollment segment (community Medicaid and originally-disabled status, and institutional); the full segment table is published in the CMS V28 model files.

How many ICD-10-CM codes map to HCC 18?

26 ICD-10-CM diagnosis codes appear in the official mapping for CMS-HCC V28 category 18 (Cancer Metastatic to Bone, Other and Unspecified Metastatic Cancer; Acute Leukemia Except Myeloid) for payment year 2026.

Which categories trump HCC 18 in the V28 hierarchy?

HCC 18 is superseded by HCC 17 (Cancer Metastatic to Lung, Liver, Brain, and Other Organs; Acute Myeloid Leukemia Except Promyelocytic). When a more severe category in the same disease group is documented, it is counted instead of HCC 18.

Related condition guides

In-depth HCC coding guides for conditions that map to category 18, with documentation tips, common mistakes, and the V24-to-V28 changes.

Related references

Sources

CMS ICD-10-CM order-file billability plus the published mapping and CMS-HCC V28 PY2026 model software. CMS-HCC V28 model published at CMS.gov Risk Adjustors; ICD-10-CM member codes from the CMS ICD-10-CM code set.

Verified current to CMS-HCC V28, payment year 2026 — last reviewed May 30, 2026.