What is ICD-10 code C52?

C52 is the ICD-10-CM diagnosis code for Malignant neoplasm of vagina. Cancer that starts in the vagina, the muscular tube connecting the uterus to the external genitalia. It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). C52 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. C52 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. C52 is a payment HCC under the CMS risk adjustment model. Under the CMS-HCC V28 risk adjustment model it maps to Bladder, Colorectal, and Other Cancers with a community, non-dual, aged base RAF weight of 0.363. Under the older CMS-HCC V24 model it maps to Colorectal, Bladder, and Other Cancers at RAF 0.307. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. HCC Buddy maintains the V28 and V24 mapping, RAF weight, and MEAT documentation criteria for C52 sourced directly from the CMS-HCC model files.

Yes. C52 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. C52 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.

What is the V28 vs V24 difference for C52?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For C52, V28 maps to Bladder, Colorectal, and Other Cancers at RAF 0.363 while V24 mapped to Colorectal, Bladder, and Other Cancers at RAF 0.307. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting C52?

Squamous cell carcinoma is the most common histological type; document this when present Distinguish vaginal cancer from cervical cancer, as treatment and prognosis differ significantly Because C52 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

C52: Malignant neoplasm of vagina — ICD-10 | Bladder, Colorectal, and Other Cancers, Colorectal

ICD-10-CM Code View

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Code lookupC52Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

C52

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

Malignant neoplasm of vagina

Cancer that starts in the vagina, the muscular tube connecting the uterus to the external genitalia.

Buddy Insight

Primary vaginal cancer is rare, accounting for only 1-2% of gynecological malignancies.

CMS-HCC V28

Mapped

HCC 22

Bladder, Colorectal, and Othe...

RAF 0.363

CMS-HCC V24

Mapped

HCC 11

Colorectal, Bladder, and Othe...

RAF 0.307

ACA/HHS

Mapped

HCC 12

HHS-HCC 12

Varies by metal level

ESRD/PACE

Mapped

HCC 11

Colorectal, Bladder, and Othe...

RAF 0.059

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

C5Malignant neoplasms of female genital organs (C51-C58)

C52Malignant neoplasm of vagina

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for C52 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for C52 in this effective period.

Related Child Codes

Official

ICD-10-CM does not list child codes under C52 for this display context.

Includes

Official

ICD-10-CM does not list Includes notes for C52 in this effective period.

Excludes 1

Official

carcinoma in situ of vagina (D07.2)

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for C52 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for C52 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for C52 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Confirmation of primary vaginal malignancy (not metastatic from another site)

Histological type (squamous cell carcinoma, adenocarcinoma, melanoma, sarcoma)

Tumor location within the vagina (upper, middle, lower third) for staging

FIGO staging

MEAT Support

HCC Buddy guidance

Confirmation of primary vaginal malignancy (not metastatic from another site)

Histological type (squamous cell carcinoma, adenocarcinoma, melanoma, sarcoma)

Tumor location within the vagina (upper, middle, lower third) for staging

FIGO staging

Audit Caution

HCC Buddy guidance

Coding a metastatic vaginal deposit as primary vaginal cancer — most vaginal malignancies are secondary

Confusing cervical cancer with vaginal involvement versus primary vaginal cancer — coding guidelines specify that cervical cancer extending into the vagina is coded as cervical primary

Not verifying whether the patient had a prior hysterectomy, which impacts whether a vaginal cuff tumor is primary or recurrent cervical cancer

Failing to distinguish between in situ and invasive disease

Common Mistakes

HCC Buddy guidance

C53.9 — Malignant neoplasm of cervix uteri; cervical cancer extending into the vagina should be coded as cervical primary, not vaginal primary

C51.9 — Malignant neoplasm of vulva; lower vaginal tumors may extend to the vulva — determine primary site

C79.82 — Secondary malignant neoplasm of genital organs; use when vaginal involvement is metastatic from another primary

D07.2 — Carcinoma in situ of vagina; preinvasive disease, not invasive malignancy

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is C52 an HCC code?

Yes. C52 maps to Bladder, Colorectal, and Other Cancers under the CMS-HCC V28 risk adjustment model (and Colorectal, Bladder, and Other Cancers under V24).

HCC Category Mapping

V28HCC 22, Bladder, Colorectal, and Other Cancers

0.363

V24HCC 11, Colorectal, Bladder, and Other Cancers

0.307

ESRDHCC 11, Colorectal, Bladder, and Other Cancers

0.059

Each model's RAF is its CMS base weight for that model's standard population, so 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 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.

Work C52 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for C52

For C52to 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 C52 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

C52 is the ICD-10-CM diagnosis code for malignant neoplasm of vagina. Cancer that starts in the vagina, the muscular tube connecting the uterus to the external genitalia. C52 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, C52 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a community, non-dual, aged base RAF weight of 0.363. Under the older CMS-HCC V24 model, C52 maps to Colorectal, Bladder, and Other Cancers (HCC 11) with a community, non-dual, aged base RAF weight of 0.307. 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.

Squamous cell carcinoma is the most common histological type; document this when present. Because C52 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 C52 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Squamous cell carcinoma is the most common histological type; document this when present
•Distinguish vaginal cancer from cervical cancer, as treatment and prognosis differ significantly

Clinical Significance

Primary vaginal cancer is rare, accounting for only 1-2% of gynecological malignancies. Most malignancies found in the vagina are metastatic from other sites (cervix, endometrium, vulva). Squamous cell carcinoma is the most common histological type, and there is a strong association with Human Papillomavirus infection and prior cervical cancer.

Documentation Requirements

✓Confirmation of primary vaginal malignancy (not metastatic from another site)
✓Histological type (squamous cell carcinoma, adenocarcinoma, melanoma, sarcoma)
✓Tumor location within the vagina (upper, middle, lower third) for staging
✓FIGO staging
✓Depth of invasion
✓Extension to adjacent structures (cervix, vulva, bladder, rectum)
✓Human Papillomavirus status if documented
✓Prior history of cervical cancer or hysterectomy

Excludes 1, Do NOT code together

carcinoma in situ of vagina (D07.2)

Commonly Confused Codes

•C53.9: Malignant neoplasm of cervix uteri; cervical cancer extending into the vagina should be coded as cervical primary, not vaginal primary
•C51.9: Malignant neoplasm of vulva; lower vaginal tumors may extend to the vulva: determine primary site
•C79.82: Secondary malignant neoplasm of genital organs; use when vaginal involvement is metastatic from another primary
•D07.2: Carcinoma in situ of vagina; preinvasive disease, not invasive malignancy

Code Hierarchy

└C52Malignant neoplasm of vagina

C52 ICD-10-CM Code: Malignant neoplasm of vagina

HCC Buddy Code Card

C52

Is C52 an HCC code?

HCC Category Mapping

MEAT Criteria for C52

Get the V28 RAF + MEAT cheat sheet

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Excludes 1, Do NOT code together

Commonly Confused Codes

Code Hierarchy

Work C52 in HCC Buddy