ICD-10-CM 2027

ICD-10 code for theca cell carcinoma

Malignant neoplasm of ovary

Header — needs a more specific code

From the official ICD-10-CM alphabetic index entry “Carcinoma (malignant) › theca cell”. Page updated September 29, 2026.

About coding theca cell carcinoma

The ICD-10-CM code for theca cell carcinoma 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.

What is the ICD-10 code for theca cell carcinoma?: C56 — Malignant neoplasm of ovary (a header code; report a more specific subcode).
Is C56 billable?: No. C56 is a header code. Report one of its more specific subcodes instead.