ICD-10-CM 2027
ICD-10 code for microscopic thymoma
From the official ICD-10-CM alphabetic index entry “Thymoma › microscopic”. Page updated September 29, 2026.
About coding microscopic thymoma
The ICD-10-CM code for microscopic thymoma is D15.0 (Benign neoplasm of thymus).
Within D15 (benign neoplasm of other and unspecified intrathoracic organs), D15.0 is specifically for benign neoplasm of thymus. Related codes cover heart (D15.1), mediastinum (D15.2), other specified intrathoracic organs (D15.7) and intrathoracic organ, unspecified (D15.9).
Don't report D15.0 together with the conditions in its Excludes1 note: benign carcinoid tumor of the thymus (D3A.091).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Don't confuse with (Excludes1 for D15.0)
- benign carcinoid tumor of the thymus (D3A.091)
Common questions about microscopic thymoma ICD-10 codes
What is the ICD-10 code for microscopic thymoma?
- D15.0 — Benign neoplasm of thymus.
Is D15.0 billable?
- Yes. D15.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can D15.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict D15.0 as a principal diagnosis.
Is D15.0 a CC or MCC?
- No. D15.0 is neither a CC nor an MCC under MS-DRG v44.0.