Z68.1 Body mass index [BMI] 19.9 or less, adult

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis. Exempt from present-on-admission (POA) reporting.

Applies from Z68 Body mass index [BMI]

Applicable to

• Kilograms per meters squared

Notes

• BMI adult codes are for use for persons 20 years of age or older
• BMI pediatric codes are for use for persons 2-19 years of age.
• These percentiles are based on the growth charts published by the Centers for Disease Control and Prevention (CDC)

MS-DRG index

Defines the logic of DRG(s) 951 in MDC 23.

Approximate ICD-9-CM (GEMs)

• V85.0 Body Mass Index less than 19, adult (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Adult diagnoses (age 15 through 124): Age conflict edit. These diagnoses are clinically expected only in patients age 15 through 124.
• Unacceptable principal diagnosis: These codes describe a circumstance which influences care but is not a current illness or injury, or capture only an underlying condition, and are unacceptable as principal diagnosis.

Code annotations containing back-references to Z68.1

Back-references to Z68.1

• Use Additional: E66 Overweight and obesity ("code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)")

Back-references to Z68

• Use Additional: E88.82 Obesity due to disruption of MC4R pathway ("code to identify body mass index (BMI), if known (Z68.-)")
• Use Additional: R63.6 Underweight ("code to identify body mass index (BMI), if known (Z68.-)")
• Use Additional: Z15.2 Genetic susceptibility to obesity ("code to identify body mass index (BMI), if known (Z68.-)")
• Use Additional: Z71.3 Dietary counseling and surveillance ("code to identify body mass index (BMI), if known (Z68.-)")

Diagnosis Index entries for Z68.1

• Body, bodies › mass index (BMI) › adult › 19.9 or less

Nearby codes

• Z68 Body mass index [BMI]
• Z68.1 Body mass index [BMI] 19.9 or less, adult (this code)
• Z68.2 Body mass index [BMI] 20-29, adult
• Z68.20 Body mass index [BMI] 20.0-20.9, adult
• Z68.21 Body mass index [BMI] 21.0-21.9, adult
• Z68.22 Body mass index [BMI] 22.0-22.9, adult
• Z68.23 Body mass index [BMI] 23.0-23.9, adult