C54.8
BillableMalignant neoplasm of overlapping sites of corpus uteri
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C54.8 an HCC code?
Yes. C54.8 maps to Melanoma and Other Skin Cancers under the CMS-HCC V28 risk adjustment model (and Breast, Prostate, and Other Cancers and Tumors under V24).
HCC Category Mapping
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 C54.8
For C54.8 to 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 C54.8 during that encounter — not just copy-forwarded from a problem list.
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 Melanoma and Other Skin Cancers (HCC 23) with a community, non-dual, aged base RAF weight of 0.251. Under the older CMS-HCC V24 model, C54.8 maps to Breast, Prostate, and Other Cancers and Tumors (HCC 12) with a community, non-dual, aged base RAF weight of 0.150. 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.
Use only when the tumor involves two or more subsites of the corpus uteri. Because C54.8 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 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