Z68 BMI codes
Category Z68 reports a patient's body mass index. Adult codes (age 20 and older) run from Z68.1 through Z68.45 in BMI ranges; pediatric codes (ages 2-19) run from Z68.51 through Z68.56 by percentile for age, based on CDC growth charts.
The official guidelines set three rules that matter for dietitians (ICD-10-CM Guidelines FY 2026):
- BMI codes are assigned only when there is an associated, reportable diagnosis (such as obesity) documented by the patient's provider.
- BMI codes are reported only as secondary diagnoses, never first.
- A dietitian's documented BMI can be used for the code, but the associated diagnosis must come from the provider. BMI codes are not assigned during pregnancy.
A claim with a Z68 code alone, or in the primary position, invites a diagnosis-related denial.
Code set changes to know: in FY 2025 pediatric Z68.54 was narrowed and Z68.55 and Z68.56 were added for higher percentiles of the 95th. For FY 2027 (dates of service from October 1, 2026), Z68.1 is replaced by Z68.18 (BMI 18.4 or less) and Z68.19 (BMI 18.5-19.9) (CMS ICD-10 files).