K59.3 – Megacolon, not elsewhere classified

ICD-10-CM 2027 diagnosis code · Other diseases of intestines

Non-billable header

ICD-10-CM code K59.3

Code: K59.3 (claims format: K593)
Description: Megacolon, not elsewhere classified
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 11. Diseases of the digestive system (K00-K95)
Block: K55-K64 Other diseases of intestines
Parent codes: K59

Billable codes under K59.3

K59.3 is a header code and cannot be used on claims. Choose the most specific code:

K59.31 – Toxic megacolonBillable
K59.39 – Other megacolonBillable

Notes for K59.3

Applicable to:

Dilatation of colon

Excludes1 (not coded here):

congenital megacolon (aganglionic) (Q43.1)
megacolon (due to) (in) Chagas' disease (B57.32)
megacolon (due to) (in) Clostridium difficile (A04.7-)
megacolon (due to) (in) Hirschsprung's disease (Q43.1)

Code first:

, if applicable (T51-T65) to identify toxic agent

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

K59 – Other functional intestinal disorders

Excludes1 (not coded here):

change in bowel habit NOS (R19.4)
intestinal malabsorption (K90.-)
psychogenic intestinal disorders (F45.8)

Excludes2 (not included here):

functional disorders of stomach (K31.-)

Related codes in K59

K59.0 – ConstipationHeader
K59.1 – Functional diarrheaBillable
K59.2 – Neurogenic bowel, not elsewhere classifiedBillable
K59.4 – Anal spasmBillable
K59.8 – Other specified functional intestinal disordersHeader
K59.9 – Functional intestinal disorder, unspecifiedBillable

Frequently asked questions

What is ICD-10 code K59.3?

K59.3 is the ICD-10-CM code for megacolon, not elsewhere classified, in the block K55-K64 (Other diseases of intestines).

Is K59.3 a billable code?

No. K59.3 is a header code with more specific child codes; report one of the billable codes listed above.

What category does K59.3 belong to?

It belongs to category K59 – Other functional intestinal disorders.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.