ICD-10-CM 2027
ICD-10 code for functional constipation
From the official ICD-10-CM alphabetic index entry “Constipation (atonic) (neurogenic) (simple) (spastic) › functional”. Page updated September 29, 2026.
About coding functional constipation
The ICD-10-CM code for functional constipation is K59.04 (Chronic idiopathic constipation).
Within K59.0 (constipation), K59.04 is specifically for chronic idiopathic constipation. Related codes cover unspecified (K59.00), slow transit constipation (K59.01), outlet dysfunction constipation (K59.02), drug induced constipation (K59.03) and other constipation (K59.09).
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 391 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC, relative weight 1.2392) and DRG 392 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC, relative weight 0.7645), in MDC 06 (Diseases and Disorders of the Digestive 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.
Common questions about functional constipation ICD-10 codes
What is the ICD-10 code for functional constipation?
- K59.04 — Chronic idiopathic constipation.
Is K59.04 billable?
- Yes. K59.04 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K59.04 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K59.04 as a principal diagnosis.
Is K59.04 a CC or MCC?
- No. K59.04 is neither a CC nor an MCC under MS-DRG v44.0.