C57.8
BillableMalignant neoplasm of overlapping sites of female genital organs
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C57.8 an HCC code?
Yes. C57.8 maps to Colorectal, Bladder, and Other Cancers under the CMS-HCC V28 risk adjustment model (and Colorectal, Bladder, and Other Cancers 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 C57.8
For C57.8 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 C57.8 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C57.8 is the ICD-10-CM diagnosis code for malignant neoplasm of overlapping sites of female genital organs. This code describes cancer that involves multiple areas of the female reproductive system (such as the uterus, ovaries, fallopian tubes, or vagina) where the tumor spans across more than one organ. It is used when the exact starting location of the cancer cannot be determined or when the cancer clearly involves overlapping structures. C57.8 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, C57.8 maps to Colorectal, Bladder, and Other Cancers (HCC 22) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, C57.8 mapped to the same category but with a base RAF weight of 0.306 — V28 recalibrated weights across the entire model. 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 this code only when the malignant neoplasm involves two or more female genital organs; if the cancer is localized to a single organ, use the specific organ-based code instead. Because C57.8 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 C57.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the malignant neoplasm involves two or more female genital organs; if the cancer is localized to a single organ, use the specific organ-based code instead
- •Review the pathology report and clinical documentation carefully to confirm that the tumor truly involves overlapping sites rather than metastatic disease to a secondary site, as metastatic cancers require different coding
Clinical Significance
This code is used when a malignant tumor involves two or more contiguous female genital organ sites and the point of origin cannot be determined. It represents a continuous tumor mass spanning multiple anatomical structures rather than metastatic spread. Accurate use requires pathologic evidence that the tumor truly overlaps structures rather than originating at one site with secondary invasion.
Documentation Requirements
- ✓Documentation identifying which specific female genital organs are involved
- ✓Pathologic evidence that the tumor spans contiguous sites (not metastatic disease)
- ✓Statement from provider that the primary origin cannot be determined
- ✓Staging information based on the composite involvement
- ✓Histologic type and grade
Commonly Confused Codes
- •C57.7 — Other specified female genital organs; use for a single specified site, not overlapping
- •C79.60-C79.62 — Secondary malignant neoplasm of ovary; metastatic disease is coded differently than overlapping primaries
- •C57.9 — Unspecified female genital organ; overlapping sites is more specific than unspecified
- •C56/C57.0 — Ovarian or fallopian tube cancer with extension should be coded to the primary site, not as overlapping