Is ICD-10-CM code K35 billable?

No, K35 (Acute appendicitis) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code K35 belong to?

K35 belongs to Chapter 11 of the ICD-10-CM tabular list: K00–K95 (Diseases of the Digestive System).

K35Non-billable

Acute appendicitis

Diseases of the Digestive System·Diseases of appendix (K35-K38)·category·FY 2026

Use a more specific code (0 billable, 3 non-billable)

K35.2Acute appendicitis with generalized peritonitishas subcodes K35.3Acute appendicitis with localized peritonitishas subcodes K35.8Other and unspecified acute appendicitishas subcodes

CH11 Parent Instructions

Excludes2(Not included here. Code separately if applicable.)

certain conditions originating in the perinatal period (P04-P96)
certain infectious and parasitic diseases (A00-B99)
complications of pregnancy, childbirth and the puerperium (O00-O9A)
congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
endocrine, nutritional and metabolic diseases (E00-E88)
injury, poisoning and certain other consequences of external causes (S00-T88)
neoplasms (C00-D49)
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Clinical Hierarchy

BillableHas subcodes

CH11Diseases of the digestive system (K00-K95)

K35-K38Diseases of appendix (K35-K38)

K35Acute appendicitisNot billable

K35.2Acute appendicitis with generalized peritonitisSubcodes

K35.3Acute appendicitis with localized peritonitisSubcodes

K35.8Other and unspecified acute appendicitisSubcodes

MS-DRG Classification

2026

No direct MS-DRG triggers identified.