ICD-10-CM 2027 diagnosis code

D40.1Neoplasm of uncertain behavior of testis

Not billable — use a more specific code

D40.1 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About D40.1

D40.1 is the ICD-10-CM diagnosis code for neoplasm of uncertain behavior of 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 a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within D40 (neoplasm of uncertain behavior of male genital organs), D40.1 is specifically for neoplasm of uncertain behavior of testis. Related codes cover prostate (D40.0), other specified male genital organs (D40.8) and male genital organ, unspecified (D40.9).

To report this condition, pick the subcode that matches the documentation: D40.10 (testis), D40.11 (testis) and D40.12 (testis).

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

Specific codes under D40.1

Notes that apply from higher levels

Instructions written at a parent level also apply to D40.1.

Broader instructions also apply from D37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes and Chapter 2: Neoplasms.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to D40.1.

Table of Drugs & Neoplasms entries

Neoplasm, neoplastic › testis, testes — Uncertain Behavior
Neoplasm, neoplastic › testis, testes › descended — Uncertain Behavior
Neoplasm, neoplastic › testis, testes › ectopic — Uncertain Behavior
Neoplasm, neoplastic › testis, testes › retained — Uncertain Behavior
Neoplasm, neoplastic › testis, testes › scrotal — Uncertain Behavior
Neoplasm, neoplastic › testis, testes › undescended — Uncertain Behavior
Neoplasm, neoplastic › testis, testes › unspecified whether descended or undescended — Uncertain Behavior

Codes whose notes reference D40.1

D44Excludes1

Code history

2016
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2021
2022
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2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about D40.1

Is D40.1 billable?: No. D40.1 is a header code. Report one of its more specific subcodes instead.