What is ICD-10 code C54.8?

C54.8 is the ICD-10-CM diagnosis code for Malignant neoplasm of overlapping sites of corpus uteri. Cancer of the uterus that involves multiple overlapping sites within the corpus (body) of the uterus, making it difficult to identify a single primary location. C54.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C54.8 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. C54.8 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. C54.8 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 C54.8 map to under V28?

C54.8 maps to CMS-HCC V28 HCC 23 (Prostate, Breast, and Other Cancers and Tumors). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM C54.8: Malignant neoplasm

C54.8 maps to CMS-HCC V28 23. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software

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 lookupC54.8

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of female genital organs (C51-C58)

C54.8

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

Malignant neoplasm of overlapping sites of corpus uteri

Cancer of the uterus that involves multiple overlapping sites within the corpus (body) of the uterus, making it difficult to identify a single primary location.

Buddy Insight

Overlapping sites of corpus uteri indicates a malignancy that spans multiple anatomical subsites within the uterine body.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 23

Prostate, Breast, and Other C...

Code-level coefficient reference

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 012

HHS-HCC 012 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 12

Breast/Prostate/and Other Can...

Code-level coefficient reference

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

C54Malignant neoplasm of corpus uteri C54.8Malignant neoplasm of overlapping sites of corpus uteri

Inclusion Terms

Official

No inclusion terms are included in this display for C54.8. Check the code and parent instructions in the Code Book.

Excludes 2

Official

No Excludes 2 notes are included in this display for C54.8. Check the code and parent instructions in the Code Book.

Related Codes

Official

C54.0Malignant neoplasm of isthmus uteri C54.1Malignant neoplasm of endometrium C54.2Malignant neoplasm of myometrium C54.3Malignant neoplasm of fundus uteri C54.9Malignant neoplasm of corpus uteri, unspecified

Includes

Official

malignant neoplasm of skin of female genital organsInherited from C51-C58

Excludes 1

Official

No Excludes 1 notes are included in this display for C54.8. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for C54.8. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C54.8. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C54.8. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Documentation that tumor involves two or more distinct sites within the corpus uteri

Identification of specific structures involved (endometrium, myometrium, fundus, isthmus)

Histological type and grade

FIGO staging

MEAT Support

HCC Buddy guidance

Documentation that tumor involves two or more distinct sites within the corpus uteri

Identification of specific structures involved (endometrium, myometrium, fundus, isthmus)

Histological type and grade

FIGO staging

Audit Caution

HCC Buddy guidance

Confusing overlapping sites (known involvement of multiple structures) with unspecified site (unknown location)

Using this code for endometrial cancer that invades the myometrium — this is staged as endometrial primary, not overlapping sites

Not documenting which specific corpus sites are involved

Defaulting to unspecified when overlapping is the more accurate designation based on pathology

Common Mistakes

HCC Buddy guidance

C54.9 — Corpus uteri, unspecified; use when the specific site is unknown, not when multiple known sites are involved

C54.1 — Endometrium; use when tumor is confined to the endometrial lining

C55 — Uterus, part unspecified; broader than corpus, includes cervix — use only when the uterine part cannot be determined

C53.8 — Overlapping sites of cervix; different anatomical region

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 C54.8 an HCC code?

Yes. C54.8 (Malignant neoplasm of overlapping sites of corpus uteri) maps to HCC 23, Prostate, Breast, and Other Cancers and Tumors under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.186. 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: C54.8 is billable and maps to V28 HCC 23, Prostate, Breast, and Other Cancers and Tumors. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: C54.8
Description: Malignant neoplasm of overlapping sites of corpus uteri
HCC (V28): HCC 23 — Prostate, Breast, and Other Cancers and Tumors
RAF reference coefficient: 0.186
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 23, Prostate, Breast, and Other Cancers and Tumors

0.186

ESRDHCC 12, Breast/Prostate/and Other Cancers and Tumors

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 C54.8 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C54.8

For C54.8, 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

Get the V28 mapping + MEAT cheat sheet

One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.

Free PDF. No card. Unsubscribe anytime.

What This Code Means

C54.8 is the ICD-10-CM diagnosis code for malignant neoplasm of overlapping sites of corpus uteri. Cancer of the uterus that involves multiple overlapping sites within the corpus (body) of the uterus, making it difficult to identify a single primary location. C54.8 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of female genital organs (c51-c58).

Under the CMS-HCC V28 risk adjustment model, C54.8 maps to Prostate, Breast, and Other Cancers and Tumors (HCC 23) with a source-labeled community, non-dual, aged reference coefficient of 0.186. No V24 mapping is shown for C54.8; use the applicable model and payment year when reviewing the V28 mapping. 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 the tumor involves two or more subsites of the corpus uteri. For C54.8, 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 C54.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use only when the tumor involves two or more subsites of the corpus uteri
•Document which specific sites are involved to support medical necessity

Clinical Significance

Overlapping sites of corpus uteri indicates a malignancy that spans multiple anatomical subsites within the uterine body. This typically represents a larger or more advanced tumor that cannot be confined to a single location such as the endometrium, myometrium, or fundus alone. The overlapping designation carries staging and treatment implications.

Documentation Requirements

✓Documentation that tumor involves two or more distinct sites within the corpus uteri
✓Identification of specific structures involved (endometrium, myometrium, fundus, isthmus)
✓Histological type and grade
✓FIGO staging
✓Extent of local invasion and depth of myometrial involvement
✓Lymph node status
✓Peritoneal cytology if applicable

Commonly Confused Codes

•C54.9: Corpus uteri, unspecified; use when the specific site is unknown, not when multiple known sites are involved
•C54.1: Endometrium; use when tumor is confined to the endometrial lining
•C55: Uterus, part unspecified; broader than corpus, includes cervix: use only when the uterine part cannot be determined
•C53.8: Overlapping sites of cervix; different anatomical region