Lower Arteries (B4) ICD-10-PCS
The B4 body system covers Imaging procedures on lower arteries, with 506 ICD-10-PCS codes across 5 root operations, 496 of them billable in fiscal year 2026. Each root operation defines a distinct procedural objective, and the info icons show the official definition with a preview of the codes inside.
Root Operations in This Body System 5 operations · 506 codes
| Chars 1–3 | Root Operation | Codes | Billable |
|---|---|---|---|
| B40 | Plain RadiographyPlanar display of an image developed from the capture of external ionizing radiation on photographic or photoconductive plate | 98 | 96 |
| B41 | FluoroscopySingle plane or bi-plane real time display of an image developed from the capture of external ionizing radiation on fluorescent screen. The image may also be stored by either digital or analog means | 212 | 210 |
| B42 | Computerized Tomography (CT Scan)Computer-reformatted digital display of multiplanar images developed from the capture of multiple exposures of external ionizing radiation | 92 | 90 |
| B43 | Magnetic Resonance Imaging (MRI)Computer reformatted digital display of multiplanar images developed from the capture of radio frequency signals emitted by nuclei in a body site excited within a magnetic field | 50 | 48 |
| B44 | UltrasonographyReal time display of images of anatomy or flow information developed from the capture of reflected and attenuated high frequency sound waves | 54 | 52 |
The info icon shows the official root operation definition and previews the codes in that range.
About the B4 Body System
The ICD-10-PCS root operation Lower Arteries (B4) within the Imaging section refers to diagnostic procedures that visualize the arteries in the lower body using various imaging technologies.
This operation captures detailed images of the lower arteries to assess blood flow, detect blockages, or guide treatment planning. Different imaging modalities are represented by specific codes: Plain Radiography (B40) uses external ionizing radiation on photographic plates to create planar images, while Fluoroscopy (B41) provides real-time visualization using a fluorescent screen. Computerized Tomography (CT Scan) (B42) produces multiplanar digital images from multiple exposures, and Magnetic Resonance Imaging (MRI) (B43) utilizes radio frequency signals within a magnetic field for detailed soft tissue contrast. Additionally, Ultrasonography (B44) offers real-time images based on high-frequency sound waves to visualize anatomy and blood flow. These lower artery imaging methods are crucial for accurate diagnosis and guiding interventions in vascular conditions.
Questions About This Page
How many codes are in the B4 body system?
The B4 body system contains 506 ICD-10-PCS codes in FY 2026, organized into 5 root operations. 496 of them are billable on inpatient claims.
What is a root operation?
The root operation is the third character of every ICD-10-PCS code and names the objective of the procedure. Drainage takes fluid out, Excision cuts out a portion of a body part, and Resection removes all of one. Picking the right root operation is the central skill of PCS coding, so each one above carries its official CMS definition.
Related References
Source: CMS FY 2026 ICD-10-PCS order file and code tables, effective October 1, 2025 through September 30, 2026.
