C57.3 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

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupC57.3

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

C57.3

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

Malignant neoplasm of parametrium

Cancer that develops in the parametrium, the connective tissue surrounding the uterus that provides structural support.

Buddy Insight

Parametrial cancer involves the connective tissue surrounding the lower portion of the uterus between the layers of the broad ligament.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 22

Bladder, Colorectal, and Othe...

Coefficient HCC 22: 0.363 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 011

HHS-HCC 011 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 10

Lymphoma and Other Cancers

Code-level coefficient reference

RXHCC

Mapped

HCC 22

Prostate, Breast, Bladder, an...

Code-level coefficient reference

Code Book Path

Official

C57Malignant neoplasm of other and unspecified female genital organs C57.3Malignant neoplasm of parametrium

Inclusion Terms

Official

Malignant neoplasm of uterine ligament NOS

Excludes 2

Official

No Excludes 2 notes are included in this display for C57.3. Check the code and parent instructions in the Code Book.

Related Codes

Official

C57.0Malignant neoplasm of fallopian tube C57.1Malignant neoplasm of broad ligament C57.2Malignant neoplasm of round ligament C57.4Malignant neoplasm of uterine adnexa, unspecified C57.7Malignant neoplasm of other specified female genital organs

Includes

Official

malignant neoplasm of skin of female genital organsInherited from C51-C58

Excludes 1

Official

No Excludes 1 notes are included in this display for C57.3. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for C57.3. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C57.3. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C57.3. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Pathology or imaging confirming parametrial malignancy

Whether the parametrial cancer is primary or secondary to cervical/uterine extension

FIGO or TNM staging

Histologic type and grade

MEAT Support

HCC Buddy guidance

Pathology or imaging confirming parametrial malignancy

Whether the parametrial cancer is primary or secondary to cervical/uterine extension

FIGO or TNM staging

Histologic type and grade

Audit Caution

HCC Buddy guidance

Coding parametrial extension of cervical cancer as C57.3 instead of the appropriate cervical primary code — parametrial extension is a staging element, not a separate primary

Failing to distinguish between primary parametrial cancer and cervical cancer with parametrial invasion

Omitting staging documentation that determines whether parametrial disease represents local extension

Common Mistakes

HCC Buddy guidance

C53.0-C53.9 — Cervical cancer codes; parametrial involvement from cervical cancer is staged differently and coded at the primary cervical site

C55 — Malignant neoplasm of uterus, part unspecified; use C57.3 only when parametrium is specifically identified

C57.4 — Uterine adnexa unspecified; parametrium is a specific identifiable structure

C57.10-C57.12 — Broad ligament cancer; parametrium is within but distinct from the broad ligament

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 C57.3 an HCC code?

Yes. C57.3 (Malignant neoplasm of parametrium) 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: C57.3 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: C57.3
Description: Malignant neoplasm of parametrium
HCC (V28): HCC 22 — Bladder, Colorectal, and Other Cancers
RAF reference coefficient: 0.363
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 22, Bladder, Colorectal, and Other Cancers

0.363

ESRDHCC 10, Lymphoma and Other Cancers

Not separately weighted

RxHCCHCC 22, Prostate, Breast, Bladder, and Other Cancers and Tumors

Not separately weighted

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 C57.3 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C57.3

For C57.3, 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

C57.3 is the ICD-10-CM diagnosis code for malignant neoplasm of parametrium. Cancer that develops in the parametrium, the connective tissue surrounding the uterus that provides structural support. C57.3 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, C57.3 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a source-labeled community, non-dual, aged reference coefficient of 0.363. 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.

Parametrial cancers are often secondary to uterine cancer; verify if this is primary or extension. For C57.3, 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 C57.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Parametrial cancers are often secondary to uterine cancer; verify if this is primary or extension
•Document whether cancer is confined to parametrium or extends to adjacent structures

Clinical Significance

Parametrial cancer involves the connective tissue surrounding the lower portion of the uterus between the layers of the broad ligament. Primary parametrial malignancies are rare; most parametrial involvement represents direct extension of cervical cancer (FIGO Stage IIB or higher). Distinguishing primary from secondary parametrial cancer is critical for accurate coding and staging.

Documentation Requirements

✓Pathology or imaging confirming parametrial malignancy
✓Whether the parametrial cancer is primary or secondary to cervical/uterine extension
✓FIGO or TNM staging
✓Histologic type and grade
✓Extent of parametrial involvement (unilateral vs. bilateral, extent to pelvic wall)
✓Active treatment versus surveillance status

Commonly Confused Codes

•C53.0-C53.9: Cervical cancer codes; parametrial involvement from cervical cancer is staged differently and coded at the primary cervical site
•C55: Malignant neoplasm of uterus, part unspecified; use C57.3 only when parametrium is specifically identified
•C57.4: Uterine adnexa unspecified; parametrium is a specific identifiable structure
•C57.10-C57.12: Broad ligament cancer; parametrium is within but distinct from the broad ligament