C57.9 ICD-10-CM Code: Malignant neoplasm of female genital organ, unspecified
C57.9 maps to CMS-HCC V28 22. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools
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FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of female genital organs (C51-C58)
C57.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMalignant neoplasm of female genital organ, unspecified
Cancer of a female genital organ when the specific organ or structure involved cannot be determined or identified.
Buddy Insight
This is the least specific code for female genital organ malignancy, used only when the provider documents cancer of a female genital organ but does not specify which organ is affected.
CMS-HCC V28
MappedHCC 22
Code-level coefficient reference
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 012
Code-level coefficient reference
ESRD/PACE
MappedHCC 11
Code-level coefficient reference
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Malignant neoplasm of female genitourinary tract NOS
Excludes 2
OfficialNo Excludes 2 notes are included in this display for C57.9. Check the code and parent instructions in the Code Book.
Related Codes
Includes
Official- malignant neoplasm of skin of female genital organsInherited from C51-C58
Excludes 1
OfficialNo Excludes 1 notes are included in this display for C57.9. Check the code and parent instructions in the Code Book.
Code First
OfficialNo Code First sequencing instructions are included in this display for C57.9. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for C57.9. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for C57.9. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 C57.9 an HCC code?
Yes. C57.9 (Malignant neoplasm of female genital organ, unspecified) maps to HCC 22, Bladder, Colorectal, and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.363. 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: C57.9 is billable and maps to V28 HCC 22, Bladder, Colorectal, and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- C57.9
- Description
- Malignant neoplasm of female genital organ, unspecified
- HCC (V28)
- HCC 22 — Bladder, Colorectal, and Other Cancers
- RAF reference coefficient
- 0.363
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
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 C57.9 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for C57.9
For C57.9, 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
C57.9 is the ICD-10-CM diagnosis code for malignant neoplasm of female genital organ, unspecified. Cancer of a female genital organ when the specific organ or structure involved cannot be determined or identified. C57.9 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, C57.9 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a source-labeled community, non-dual, aged reference coefficient of 0.363. No V24 mapping is shown for C57.9; 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.
This is the least specific code in the C57 category; attempt to obtain more specific site information. For C57.9, 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 C57.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is the least specific code in the C57 category; attempt to obtain more specific site information
- •Request clarification from the provider if the cancer location is not documented
Clinical Significance
This is the least specific code for female genital organ malignancy, used only when the provider documents cancer of a female genital organ but does not specify which organ is affected. In risk adjustment, this code raises red flags for insufficient documentation and is a prime target for coding audits. Provider queries should always be pursued before defaulting to this code.
Documentation Requirements
- ✓Documentation of a confirmed malignancy of a female genital organ
- ✓Evidence that provider query was attempted to identify the specific organ
- ✓Explanation of why the specific organ cannot be determined
- ✓Current treatment status and plan
Commonly Confused Codes
- •C56.1/C56.2/C56.9: Ovarian cancer; query provider if ovary might be the site
- •C55: Uterine cancer unspecified; if uterus is mentioned, use C55 rather than C57.9
- •C57.4: Uterine adnexa unspecified; more specific than C57.9 if adnexa is mentioned
- •C57.7: Other specified female genital organs; use when a specific organ is named