ICD-10-CM 2027 diagnosis code
K59.8Other specified functional intestinal disorders
K59.8 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.
Code last changed in FY2021 (effective October 1, 2020). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About K59.8
K59.8 is the ICD-10-CM diagnosis code for other specified functional intestinal disorders. It belongs to category K59 (other functional intestinal disorders), block K55-K64 (other diseases of intestines) and chapter 11 (diseases of the digestive system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.
Within K59, choose K59.8 (Other specified functional intestinal disorders) only when documentation doesn't support a more specific option: constipation (K59.0), functional diarrhea (K59.1), neurogenic bowel, not elsewhere classified (K59.2), megacolon, not elsewhere classified (K59.3), anal spasm (K59.4) and functional intestinal disorder, unspecified (K59.9).
To report this condition, pick the subcode that matches the documentation: K59.81 (syndrome) and K59.89 (disorders).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2021 (expanded into subcodes).
Before ICD-10, this condition was coded in ICD-9-CM as 564.89 (other functional disorders of intestine).
Specific codes under K59.8
Notes that apply from higher levels
Instructions written at a parent level also apply to K59.8.
Broader instructions also apply from Chapter 11: Diseases of the digestive system.
ICD-9-CM equivalent
Converter →- 564.89Other functional disorders of intestineexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- FY2021 (effective 10/1/2020): Expanded — no longer billable