C56 Malignant neoplasm of ovary

The ICD-10-CM code for Malignant neoplasm of ovary is C56 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter

2: Neoplasms (C00-D49)

Section

C51-C58: Malignant neoplasms of female genital organs (C51-C58)

Category C56

5 codes (4 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to C56:

• Thecoma › malignant
• Dermoid (cyst) › with malignant transformation
• Carcinoma (malignant) › granulosa cell
• Tumor › dermoid › with malignant transformation
• Adenofibroma › endometrioid › malignant
• Teratoma (solid) › ovary › embryonal, immature or malignant
• Brenner › tumor (benign) › malignant
• Tumor › Brenner › malignant

Official Coding Guidelines

Tx of primary site (TOC entry)

a. Admission/Encounter for treatment of primary site ............................................................. 33

Tx of secondary site (TOC entry)

b. Admission/Encounter for treatment of secondary site .......................................................... 33

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool