R63.6

Billable

Underweight

R63.6 is the ICD-10-CM code for Underweight. It is a billable, specific code valid for reimbursement.

Status
Billable
Chapter
R00-R99
Parent
R63
Edition
FY2026

R00-R99 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified

Excludes1 — not coded here

  • abnormal weight loss (R63.4)
  • anorexia nervosa (F50.0-)
  • malnutrition (E40-E46)

Use additional code

  • code to identify body mass index (BMI), if known (Z68.-)

Frequently asked questions

What is ICD-10 code R63.6?
R63.6 is the ICD-10-CM code for "Underweight". It falls under R00-R99 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified.
Is R63.6 a billable code?
Yes — R63.6 is a billable, specific ICD-10-CM code valid for reimbursement.
What is excluded from R63.6?
Excludes1 (not coded here): abnormal weight loss (R63.4); anorexia nervosa (F50.0-); malnutrition (E40-E46).

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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