R63.6
Billable codeUnderweight
The ICD-10 code for underweight is R63.6.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
Use additional code
This code represents an underlying condition. When a related manifestation is also present, coding convention calls for an additional code to be listed after this one.
- code to identify body mass index (BMI), if known (Z68.-)
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •If the associated manifestation or related condition noted above is also documented, an additional code should be reported alongside this one.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 78322
Associated MS-DRGs
R63.6 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.
Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.