| K55.0 | Acute vascular disorders of intestine | NON-BILLABLE CODE |
| K55.01 | Acute (reversible) ischemia of small intestine | NON-BILLABLE CODE |
| K55.011 | Focal (segmental) acute (reversible) ischemia of small intestine | BILLABLE CODE |
| K55.012 | Diffuse acute (reversible) ischemia of small intestine | BILLABLE CODE |
| K55.019 | Acute (reversible) ischemia of small intestine, extent unspecified | BILLABLE CODE |
| K55.02 | Acute infarction of small intestine | NON-BILLABLE CODE |
| K55.021 | Focal (segmental) acute infarction of small intestine | BILLABLE CODE |
| K55.022 | Diffuse acute infarction of small intestine | BILLABLE CODE |
| K55.029 | Acute infarction of small intestine, extent unspecified | BILLABLE CODE |
| K55.03 | Acute (reversible) ischemia of large intestine | NON-BILLABLE CODE |
| K55.031 | Focal (segmental) acute (reversible) ischemia of large intestine | BILLABLE CODE |
| K55.032 | Diffuse acute (reversible) ischemia of large intestine | BILLABLE CODE |
| K55.039 | Acute (reversible) ischemia of large intestine, extent unspecified | BILLABLE CODE |
| K55.04 | Acute infarction of large intestine | NON-BILLABLE CODE |
| K55.041 | Focal (segmental) acute infarction of large intestine | BILLABLE CODE |
| K55.042 | Diffuse acute infarction of large intestine | BILLABLE CODE |
| K55.049 | Acute infarction of large intestine, extent unspecified | BILLABLE CODE |
| K55.05 | Acute (reversible) ischemia of intestine, part unspecified | NON-BILLABLE CODE |
| K55.051 | Focal (segmental) acute (reversible) ischemia of intestine, part unspecified | BILLABLE CODE |
| K55.052 | Diffuse acute (reversible) ischemia of intestine, part unspecified | BILLABLE CODE |
| K55.059 | Acute (reversible) ischemia of intestine, part and extent unspecified | BILLABLE CODE |
| K55.06 | Acute infarction of intestine, part unspecified | NON-BILLABLE CODE |
| K55.061 | Focal (segmental) acute infarction of intestine, part unspecified | BILLABLE CODE |
| K55.062 | Diffuse acute infarction of intestine, part unspecified | BILLABLE CODE |
| K55.069 | Acute infarction of intestine, part and extent unspecified | BILLABLE CODE |
| K55.1 | Chronic vascular disorders of intestine | BILLABLE CODE |
| K55.2 | Angiodysplasia of colon | NON-BILLABLE CODE |
| K55.20 | Angiodysplasia of colon without hemorrhage | BILLABLE CODE |
| K55.21 | Angiodysplasia of colon with hemorrhage | BILLABLE CODE |
| K55.3 | Necrotizing enterocolitis | NON-BILLABLE CODE |
| K55.30 | Necrotizing enterocolitis, unspecified | BILLABLE CODE |
| K55.31 | Stage 1 necrotizing enterocolitis | BILLABLE CODE |
| K55.32 | Stage 2 necrotizing enterocolitis | BILLABLE CODE |
| K55.33 | Stage 3 necrotizing enterocolitis | BILLABLE CODE |
| K55.8 | Other vascular disorders of intestine | BILLABLE CODE |
| K55.9 | Vascular disorder of intestine, unspecified | BILLABLE CODE |
