Excludes1 pair
N18.9 vs N28.9
N18.9 and N28.9 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on N28.9
chronic renal insufficiency (N18.9)
N18.9
Chronic kidney disease, unspecified
BillableUnspecified
- Chapter 14
- Diseases of the genitourinary system
- Section
- N17-N19
Use when the record says
- Chronic renal disease
- Chronic renal failure NOS
- Chronic renal insufficiency
- Chronic uremia NOS
- Diffuse sclerosing glomerulonephritis NOS
Indexed under
- Apoplexia, apoplexy, apoplectic › uremic
- Glomerulonephritis › sclerosing, diffuse
- Neuropathy, neuropathic › uremic
- Paralysis, paralytic › uremic
- Pericarditis › uremic
N28.9
Disorder of kidney and ureter, unspecified
BillableUnspecified
- Chapter 14
- Diseases of the genitourinary system
- Section
- N25-N29
Use when the record says
- Nephropathy NOS
- Renal disease (acute) NOS
- Renal insufficiency (acute)
Indexed under
- Inefficiency, kidney
- Nephropathy
- Shutdown, renal
- Block, blocked › kidney
- Cachexia › renal
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027