ICD-10-CM 2027
ICD-10 code for malignant thecoma
From the official ICD-10-CM alphabetic index entry “Thecoma › malignant”. Page updated September 29, 2026.
About coding malignant thecoma
The ICD-10-CM code for malignant thecoma is C56 (Malignant neoplasm of ovary).
To report this condition, pick the subcode that matches the documentation: C56.1 (ovary), C56.2 (ovary), C56.3 (ovaries) and C56.9 (ovary).
Use an additional code to identify any functional activity.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.