2026 ICD-10-CM Diagnosis Code Z3AWeeks of gestation

ICD-10-CM Codes›Z00–Z99›Z30-Z39›Z3A

ICD-10-CM Z3A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z3A is a non-billable ICD-10-CM category code for weeks of gestation, so it cannot be submitted on claims. Use a more specific code from this category instead, such as Z3A.00, Z3A.01, Z3A.08, and Z3A.09.

Code Identity

ICD-10-CM Code
Z3A
Billable Status
No — Non-Billable Category
Code Describes
Weeks of gestation
Short Description
Weeks of gestation
Same as the full description in the CMS dataset.
Chapter
Z30-Z39
Persons encountering health services in circumstances related to reproduction

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ30-Z39Persons encountering health services in circumstances related to reproduction
CategoryZ3AWeeks of gestation
This CodeZ3AWeeks of gestation

Specific Coding for Weeks of gestationOverview

Non-specific codes like Z3A require more characters. Use one of these billable codes instead:

  • Z3A.0 for Weeks of gestation of pregnancy, unspecified or less than 10 weeks

  • Use Z3A.00 for Weeks of gestation of pregnancy not specified

  • Use Z3A.01 for Less than 8 weeks gestation of pregnancy

  • Use Z3A.08 for 8 weeks gestation of pregnancy

  • Use Z3A.09 for 9 weeks gestation of pregnancy

  • Z3A.1 for Weeks of gestation of pregnancy, weeks 10-19

  • Use Z3A.10 for 10 weeks gestation of pregnancy

  • Use Z3A.11 for 11 weeks gestation of pregnancy

  • Use Z3A.12 for 12 weeks gestation of pregnancy

  • Use Z3A.13 for 13 weeks gestation of pregnancy

  • Use Z3A.14 for 14 weeks gestation of pregnancy

  • Use Z3A.15 for 15 weeks gestation of pregnancy

  • Use Z3A.16 for 16 weeks gestation of pregnancy

  • Use Z3A.17 for 17 weeks gestation of pregnancy

  • Use Z3A.18 for 18 weeks gestation of pregnancy

  • Use Z3A.19 for 19 weeks gestation of pregnancy

  • Z3A.2 for Weeks of gestation of pregnancy, weeks 20-29

  • Use Z3A.20 for 20 weeks gestation of pregnancy

  • Use Z3A.21 for 21 weeks gestation of pregnancy

  • Use Z3A.22 for 22 weeks gestation of pregnancy

  • Use Z3A.23 for 23 weeks gestation of pregnancy

  • Use Z3A.24 for 24 weeks gestation of pregnancy

  • Use Z3A.25 for 25 weeks gestation of pregnancy

  • Use Z3A.26 for 26 weeks gestation of pregnancy

  • Use Z3A.27 for 27 weeks gestation of pregnancy

  • Use Z3A.28 for 28 weeks gestation of pregnancy

  • Use Z3A.29 for 29 weeks gestation of pregnancy

  • Z3A.3 for Weeks of gestation of pregnancy, weeks 30-39

  • Use Z3A.30 for 30 weeks gestation of pregnancy

  • Use Z3A.31 for 31 weeks gestation of pregnancy

  • Use Z3A.32 for 32 weeks gestation of pregnancy

  • Use Z3A.33 for 33 weeks gestation of pregnancy

  • Use Z3A.34 for 34 weeks gestation of pregnancy

  • Use Z3A.35 for 35 weeks gestation of pregnancy

  • Use Z3A.36 for 36 weeks gestation of pregnancy

  • Use Z3A.37 for 37 weeks gestation of pregnancy

  • Use Z3A.38 for 38 weeks gestation of pregnancy

  • Use Z3A.39 for 39 weeks gestation of pregnancy

  • Z3A.4 for Weeks of gestation of pregnancy, weeks 40 or greater

  • Use Z3A.40 for 40 weeks gestation of pregnancy

  • Use Z3A.41 for 41 weeks gestation of pregnancy

  • Use Z3A.42 for 42 weeks gestation of pregnancy

  • Use Z3A.49 for Greater than 42 weeks gestation of pregnancy

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Code First

  • Codes from category Z3A are for use, only on the maternal record, to indicate the weeks of gestation of the pregnancy, if known.

Patient EducationClinical

Pregnancy

You're going to have a baby! It's an exciting time, but it can also feel a bit overwhelming. You may have a lot of questions, including what you can do to give your baby a healthy start. Taking care of your health while you're pregnant will help your fetus develop into a healthy baby. To do that, it's important to:

Read the full article at MedlinePlus

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

Code HistoryHistory

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

Questions About Z3AOverview

Is Z3A (Weeks of gestation) a billable code?

No. This is a category header that groups the codes for weeks of gestation, and headers cannot be submitted on claims. Claims for weeks of gestation need a more specific code from this category, such as Z3A.00, Z3A.01, and Z3A.08.