D40.10Neoplasm of uncertain behavior of unspecified testis

D40.10 is the ICD-10-CM diagnosis code for neoplasm of uncertain behavior of unspecified testis. It belongs to category D40 (neoplasm of uncertain behavior of male genital organs), block D37-D48 (neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within D40.1, choose D40.10 (unspecified testis) only when documentation doesn't support a more specific option: right testis (D40.11) and left testis (D40.12).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 715 (Male Reproductive System and Other O.R. Procedures for Malignancy with CC/MCC, relative weight 2.2906), DRG 716 (Male Reproductive System and Other O.R. Procedures for Malignancy without CC/MCC, relative weight 1.4619), DRG 722 (Malignancy, Male Reproductive System with MCC, relative weight 1.6689), DRG 723 (Malignancy, Male Reproductive System with CC, relative weight 1.0697) and DRG 724 (Malignancy, Male Reproductive System without CC/MCC, relative weight 0.5901), in MDC 12 (Diseases and Disorders of the Male Reproductive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is on the CMS list of diagnoses consistent only with male patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 236.4 (neoplasm of uncertain behavior of testis).