C54.2
BillableMalignant neoplasm of myometrium
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C54.2 an HCC code?
Yes. C54.2 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 C54.2
For C54.2 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 C54.2 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C54.2 is the ICD-10-CM diagnosis code for malignant neoplasm of myometrium. Cancer that develops in the myometrium, which is the muscular layer of the uterus. This is a less common type of uterine cancer. C54.2 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, C54.2 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, C54.2 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.
Distinguish between myometrial sarcomas and carcinomas, as treatment differs significantly. Because C54.2 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 C54.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Distinguish between myometrial sarcomas and carcinomas, as treatment differs significantly
- •Ensure documentation specifies myometrium involvement rather than endometrial involvement
Clinical Significance
Malignant neoplasm of the myometrium represents cancer originating in the muscular wall of the uterus. Myometrial malignancies are typically sarcomas (leiomyosarcoma, endometrial stromal sarcoma) rather than carcinomas, making them clinically distinct from the more common endometrial cancers. These tumors tend to be more aggressive with different treatment protocols.
Documentation Requirements
- ✓Specific site confirmed as myometrium (muscular layer)
- ✓Histological type (leiomyosarcoma, endometrial stromal sarcoma, undifferentiated sarcoma)
- ✓Differentiation from endometrial carcinoma invading the myometrium versus primary myometrial tumor
- ✓Tumor size and extent
- ✓FIGO staging
- ✓Mitotic rate (critical for distinguishing leiomyosarcoma from leiomyoma)
- ✓Lymph node and distant metastasis assessment