R63.4 vs R63.6
R63.4 and R63.6 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on R63.6
abnormal weight loss (R63.4)
R63.4
Abnormal weight loss
Billable
- Chapter 18
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Section
- R50-R69
Indexed under
- Loss › weight (of)
- Weight › loss
- Abnormal, abnormality, abnormalities › loss of › weight
- Excess, excessive, excessively › weight › loss
R63.6
Underweight
Billable
- Chapter 18
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Section
- R50-R69
Indexed under
- Underweight
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