2026 ICD-10-CM Diagnosis Code Z68.51Body mass index [BMI] pediatric, less than 5th percentile for age

ICD-10-CM Codes›Z00–Z99›BMI›Z68

ICD-10-CM Z68.51
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z68.51 is a billable ICD-10-CM diagnosis code for body mass index [BMI] pediatric, less than 5th percentile for age. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified status.

Code Identity

ICD-10-CM Code
Z68.51
Billable Status
Yes — Valid for Submission
Code Describes
Body mass index [BMI] pediatric, less than 5th percentile for age
Short Description
Body mass index pediatric, less than 5th percentile for age
Parent Code
Z68.5
Body mass index [BMI] pediatric

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionBMIBody mass index (Z68)
CategoryZ68Body mass index [BMI]
This CodeZ68.51Body mass index [BMI] pediatric, less than 5th percentile for age

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z68.51.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

Z68.51 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Body, bodies
      • mass index (BMI)
        • pediatric
          • less than fifth percentile for age

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC025
Other specified status
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Body Weight

Body weight is the total mass of your body. Keeping track of your weight is one way to check for changes in your health, but it can't tell you the whole story. That's because your weight includes muscle, bone, fat, and water. Also, everyday factors can play a role in your weight, such as your:

The full article covers:

  • What is body weight?
  • What factors help determine a healthy body weight?
  • What are body weight ranges?
  • What if I have a sudden gain or loss of weight?
  • How can I maintain a healthy body weight?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Z68.51 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V85.51 BMI,pediatric <5%
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2020No changes
FY 2021RevisedCode revised
FY 2022–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z68.51Overview

Is Z68.51 (Body mass index [BMI] pediatric) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report body mass index [BMI] pediatric, less than 5th percentile for age on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z68.51 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because body mass index [BMI] pediatric, less than 5th percentile for age describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z68.51 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for body mass index [BMI] pediatric, less than 5th percentile for age on inpatient claims.

What is the ICD-9 equivalent of Z68.51?

Under the General Equivalence Mappings, body mass index [BMI] pediatric, less than 5th percentile for age converts to ICD-9-CM V85.51 (BMI,pediatric <5%). The mapping is a direct match.