R63.6 — Underweight
R63.6 is a billable, specific ICD-10-CM code for underweight. It is valid for submission on a claim.
Excludes1 — never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
Use additional code
Add a secondary code to capture the detail described below.
- code to identify body mass index (BMI), if known (Z68.-)
Risk adjustment
R63.6 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
R63.6 is named in 2 Medicare coverage policies — 2 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A57063Billing and Coding: Diagnostic and Therapeutic Esophagogastroduodenoscopy
- A57189Billing and Coding: Serum Magnesium
How R63.6 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to R63.6.
- Underweight
Related codes at this level
Codes that share R63. If R63.6 is not quite right, the correct code is usually one of these.
Questions about R63.6
- Is R63.6 a billable ICD-10-CM code?
- Yes. R63.6 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does R63.6 sit in the tabular list?
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99), in the block General symptoms and signs (R50-R69).
- What cannot be coded together with R63.6?
- R63.6 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.