BY4 Ultrasonography - Fetus and Obstetrical ICD-10-PCS
The BY4 code range contains 9 ICD-10-PCS codes for Ultrasonography procedures on the fetus and obstetrical. 8 of the codes are billable and valid for inpatient claim submission in fiscal year 2026.
Root Operation Definition
Ultrasonography: Real time display of images of anatomy or flow information developed from the capture of reflected and attenuated high frequency sound waves.
Codes in the BY4 Range 9 codes · 8 billable
- BY4 Imaging, Fetus and Obstetrical, UltrasonographyNon-billable header
- BY47ZZZ Ultrasonography of Fetal Umbilical Cord
- BY48ZZZ Ultrasonography of Placenta
- BY49ZZZ Ultrasonography of First Trimester, Single Fetus
- BY4BZZZ Ultrasonography of First Trimester, Multiple Gestation
- BY4CZZZ Ultrasonography of Second Trimester, Single Fetus
- BY4DZZZ Ultrasonography of Second Trimester, Multiple Gestation
- BY4FZZZ Ultrasonography of Third Trimester, Single Fetus
- BY4GZZZ Ultrasonography of Third Trimester, Multiple Gestation
About the BY4 Code Range
The ICD-10-PCS root operation Ultrasonography (BY4) refers to the use of ultrasound imaging to visualize and assess fetal and obstetrical structures within the body. This imaging procedure captures internal images without any incision or radiation exposure.
Within the Imaging section, Ultrasonography is crucial for monitoring fetal development and obstetrical conditions throughout pregnancy. The provided codes specify ultrasound exams targeted at various body parts and pregnancy stages, such as ultrasonography of the Fetal Umbilical Cord (BY47ZZZ), Placenta (BY48ZZZ), or evaluation of a Single Fetus in the first trimester (BY49ZZZ) or third trimester (BY4FZZZ). Other codes delineate studies of Multiple Gestations across trimesters like BY4BZZZ and BY4GZZZ. These specialized codes enable precise documentation of fetal imaging procedures, supporting accurate coding and effective clinical communication.
Questions About This Page
How many billable codes are in the BY4 range?
Of the 9 codes in this range, 8 are billable and valid for inpatient claim submission from October 1, 2025 through September 30, 2026. Table header codes group them but cannot be reported on claims.
What does the BY4 range classify?
The range classifies Ultrasonography procedures, real time display of images of anatomy or flow information developed from the capture of reflected and attenuated high frequency sound waves, performed on the fetus and obstetrical. Each code adds the body part, approach, device, and qualifier in characters four through seven, and links to its own reference page.
Related References
Source: CMS FY 2026 ICD-10-PCS order file and code tables, effective October 1, 2025 through September 30, 2026.
