C22.8 maps to CMS-HCC V28 20. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

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 lookupC22.8

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of digestive organs (C15-C26)

C22.8

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

Malignant neoplasm of liver, primary, unspecified as to type

A primary liver cancer where the specific type or cell origin has not been determined or specified in the medical documentation.

Buddy Insight

Primary liver cancer, unspecified as to type, is used when there is confirmed primary malignancy of the liver but the specific histological type has not been determined.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 20

Lung and Other Severe Cancers

Coefficient HCC 20: 1.136 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 009

HHS-HCC 009 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 9

Lung and Other Severe Cancers

Code-level coefficient reference

RXHCC

Mapped

HCC 20

Lung, Kidney, and Other Cance...

Code-level coefficient reference

Code Book Path

Official

C22Malignant neoplasm of liver and intrahepatic bile ducts C22.8Malignant neoplasm of liver, primary, unspecified as to type

Inclusion Terms

Official

No inclusion terms are included in this display for C22.8. Check the code and parent instructions in the Code Book.

Excludes 2

Official

gastrointestinal stromal tumors (C49.A-)Inherited from C15-C26

Related Codes

Official

C22.0Liver cell carcinoma C22.1Intrahepatic bile duct carcinoma C22.2Hepatoblastoma C22.3Angiosarcoma of liver C22.4Other sarcomas of liver

Includes

Official

No Includes notes are included in this display for C22.8. Check the code and parent instructions in the Code Book.

Excludes 1

Official

Kaposi's sarcoma of gastrointestinal sites (C46.4)Inherited from C15-C26, C22
malignant neoplasm of biliary tract NOS (C24.9)Inherited from C15-C26, C22
secondary malignant neoplasm of liver and intrahepatic bile duct (C78.7)Inherited from C15-C26, C22

Code First

Official

No Code First sequencing instructions are included in this display for C22.8. Check the code and parent instructions in the Code Book.

Use Additional

Official

code to identify:Inherited from C22
alcohol abuse and dependence (F10.-)Inherited from C22
hepatitis B (B16.-, B18.0-B18.1)Inherited from C22
hepatitis C (B17.1-, B18.2)Inherited from C22

Code Also

Official

No Code Also instructions are included in this display for C22.8. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Confirmation that the cancer is primary to the liver (not metastatic)

Documentation that the specific histological type is unknown or not yet determined

Imaging characteristics suggesting primary liver malignancy

Alpha-fetoprotein and other tumor markers if obtained

MEAT Support

HCC Buddy guidance

Confirmation that the cancer is primary to the liver (not metastatic)

Documentation that the specific histological type is unknown or not yet determined

Imaging characteristics suggesting primary liver malignancy

Alpha-fetoprotein and other tumor markers if obtained

Audit Caution

HCC Buddy guidance

Confusing C22.8 (primary, type unknown) with C22.9 (unknown if primary or secondary) — these are distinct clinical scenarios

Using C22.8 when pathology has already determined the type — always use the most specific code available

Not recognizing that liver metastases are far more common than primary liver cancer, requiring careful verification of primary status

Failing to update the code when pathology results become available

Common Mistakes

HCC Buddy guidance

C22.0 — Hepatocellular carcinoma: use when hepatocellular type is confirmed

C22.1 — Intrahepatic cholangiocarcinoma: use when bile duct carcinoma is confirmed

C22.9 — Liver cancer, not specified as primary or secondary: C22.8 is for confirmed primary but unknown type; C22.9 is for unknown origin (primary vs secondary)

C78.7 — Secondary malignant neoplasm of liver: metastatic liver cancer; must exclude this before using C22.8

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 C22.8 an HCC code?

Yes. C22.8 (Malignant neoplasm of liver, primary, unspecified as to type) maps to HCC 20, Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.136. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: C22.8 is billable and maps to V28 HCC 20, Lung and Other Severe Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C22.8
Description: Malignant neoplasm of liver, primary, unspecified as to type
HCC (V28): HCC 20 — Lung and Other Severe Cancers
RAF reference coefficient: 1.136
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 20, Lung and Other Severe Cancers

1.136

ESRDHCC 9, Lung and Other Severe Cancers

Not separately weighted

RxHCCHCC 20, Lung, Kidney, and Other Cancers; Secondary Cancer of Lymph Nodes and Other Sites

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. 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 context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work C22.8 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C22.8

For C22.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

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

Coder workflow notes

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What This Code Means

C22.8 is the ICD-10-CM diagnosis code for malignant neoplasm of liver, primary, unspecified as to type. A primary liver cancer where the specific type or cell origin has not been determined or specified in the medical documentation. C22.8 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of digestive organs (c15-c26).

Under the CMS-HCC V28 risk adjustment model, C22.8 maps to Lung and Other Severe Cancers (HCC 20) with a source-labeled community, non-dual, aged reference coefficient of 1.136. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Use only when histological type is unknown or not documented. For C22.8, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for C22.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use only when histological type is unknown or not documented
•Query provider if pathology results are available to assign more specific code

Clinical Significance

Primary liver cancer, unspecified as to type, is used when there is confirmed primary malignancy of the liver but the specific histological type has not been determined. This may occur when biopsy has not been performed or pathology results are pending. While this code carries the same HCC weight as specified liver cancer codes, determining the specific type is critical for treatment decisions, as hepatocellular carcinoma, cholangiocarcinoma, and other types have fundamentally different management strategies.

Documentation Requirements

✓Confirmation that the cancer is primary to the liver (not metastatic)
✓Documentation that the specific histological type is unknown or not yet determined
✓Imaging characteristics suggesting primary liver malignancy
✓Alpha-fetoprotein and other tumor markers if obtained
✓Planned workup to determine specific type

Commonly Confused Codes

•C22.0: Hepatocellular carcinoma: use when hepatocellular type is confirmed
•C22.1: Intrahepatic cholangiocarcinoma: use when bile duct carcinoma is confirmed
•C22.9: Liver cancer, not specified as primary or secondary: C22.8 is for confirmed primary but unknown type; C22.9 is for unknown origin (primary vs secondary)
•C78.7: Secondary malignant neoplasm of liver: metastatic liver cancer; must exclude this before using C22.8