ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview

The International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) code group BY4C includes procedures performed to image fetal anatomy and flow information in the second trimester for a single fetus. These ICD-10-PCS codes are used for inpatient documentation when a real-time ultrasonography study is performed to evaluate fetal development, anatomy, or hemodynamics in a pregnancy with a single fetus. Accurate coding within the ICD-10-PCS BY4C group is essential for proper inpatient reimbursement, as it captures the specific procedure performed and supports clinical documentation accuracy.

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Second Trimester, Single Fetus Ultrasonography Procedure Overview

This procedure group includes real-time display ultrasonography performed on a single fetus during the second trimester and targets the fetus and obstetrical body system. Procedures capture reflected and attenuated high-frequency sound waves to develop images or flow information used for assessment of fetal anatomy and well-being. Accurate ICD-10-PCS coding of these procedures supports correct inpatient documentation and helps determine appropriate case mix and payment.

Code Attributes

Character	ICD-10-PCS Category	Code Group Details
B	Section	Imaging
Y	Body System	Fetus and Obstetrical
4	Operation	Ultrasonography
C	Body Part	Second Trimester, Single Fetus

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ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview

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Second Trimester, Single Fetus Ultrasonography Procedure Overview

Code Attributes

Character	ICD-10-PCS Category	Code Group Details
B	Section	Imaging
Y	Body System	Fetus and Obstetrical
4	Operation	Ultrasonography
C	Body Part	Second Trimester, Single Fetus

When to Use

Use a code from this group when an inpatient ultrasonography examination is performed specifically for a single fetus in the second trimester to evaluate anatomy or circulatory flow. Select the code that matches the documented operation and fetal status to ensure precise inpatient procedure reporting.

ICD-10-PCS Codes

1 rows

ICD-10-PCS Code	Description
BY4CZZZ	Ultrasonography of Second Trimester, Single Fetus

Typical Clinical Scenarios

A 28-year-old woman at 20 weeks gestation with a previously uncomplicated pregnancy is admitted for routine inpatient maternal-fetal assessment due to abnormal serum screening results suggesting increased risk for structural anomaly. An inpatient real-time ultrasonography study is performed to evaluate fetal anatomy and growth of the single fetus during the second trimester. The imaging targets development of organs and measurements to clarify screening findings and guide further care. Typical codes: BY4CZZZ
A 32-year-old woman presents to labor and delivery with sudden onset of vaginal bleeding at 22 weeks gestation and single live fetus on prior outpatient ultrasound. She is admitted for observation and an urgent inpatient ultrasonography exam is performed to assess fetal anatomy, viability, placental location, and fetal hemodynamics in the second trimester. Real-time imaging guides immediate clinical decisions about maternal stabilization and fetal monitoring. Typical codes: BY4CZZZ
A 35-year-old woman with a single fetus at 24 weeks gestation and a prior inconclusive ultrasound due to suboptimal visualization is admitted for repeat inpatient imaging. A focused second-trimester real-time ultrasonography study is performed to reassess fetal structures and flow information to resolve previous diagnostic uncertainty and plan further management. Repeat imaging is used because prior study limitations could affect care decisions. Typical codes: BY4CZZZ

ICD-10-PCS Code For Fetal Umbilical Cord: Procedure Code Group Overview

BY48-PLACENTA-ULTRASONOGRAPHY

ICD-10-PCS Code For Placenta: Procedure Code Group Overview

BY49-FIRST-TRIMESTER-SINGLE-FETUS-ULTRASONOGRAPHY

ICD-10-PCS Code For First Trimester Single Fetus: Procedure Code Group Overview

BY4B-FIRST-TRIMESTER-MULTIPLE-GESTATION-ULTRASONOGRAPHY

ICD-10-PCS Code For First Trimester, Multiple Gestation: Procedure Code Group Overview

BY4D-SECOND-TRIMESTER-MULTIPLE-GESTATION-ULTRASONOGRAPHY

ICD-10-PCS Code For Second Trimester, Multiple Gestation: Procedure Code Group Overview

BY4F-THIRD-TRIMESTER-SINGLE-FETUS-ULTRASONOGRAPHY

ICD-10-PCS Code For Third Trimester Single Fetus: Procedure Code Group Overview

BY4G-THIRD-TRIMESTER-MULTIPLE-GESTATION-ULTRASONOGRAPHY

ICD-10-PCS Code For Third Trimester, Multiple Gestation: Procedure Code Group Overview

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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When to Use

ICD-10-PCS Codes

1 rows

ICD-10-PCS Code	Description
BY4CZZZ	Ultrasonography of Second Trimester, Single Fetus

Typical Clinical Scenarios

A 28-year-old woman at 20 weeks gestation with a previously uncomplicated pregnancy is admitted for routine inpatient maternal-fetal assessment due to abnormal serum screening results suggesting increased risk for structural anomaly. An inpatient real-time ultrasonography study is performed to evaluate fetal anatomy and growth of the single fetus during the second trimester. The imaging targets development of organs and measurements to clarify screening findings and guide further care. Typical codes: BY4CZZZ
A 32-year-old woman presents to labor and delivery with sudden onset of vaginal bleeding at 22 weeks gestation and single live fetus on prior outpatient ultrasound. She is admitted for observation and an urgent inpatient ultrasonography exam is performed to assess fetal anatomy, viability, placental location, and fetal hemodynamics in the second trimester. Real-time imaging guides immediate clinical decisions about maternal stabilization and fetal monitoring. Typical codes: BY4CZZZ
A 35-year-old woman with a single fetus at 24 weeks gestation and a prior inconclusive ultrasound due to suboptimal visualization is admitted for repeat inpatient imaging. A focused second-trimester real-time ultrasonography study is performed to reassess fetal structures and flow information to resolve previous diagnostic uncertainty and plan further management. Repeat imaging is used because prior study limitations could affect care decisions. Typical codes: BY4CZZZ

ICD-10-PCS Code For Fetal Umbilical Cord: Procedure Code Group Overview

BY48-PLACENTA-ULTRASONOGRAPHY

ICD-10-PCS Code For Placenta: Procedure Code Group Overview

BY49-FIRST-TRIMESTER-SINGLE-FETUS-ULTRASONOGRAPHY

ICD-10-PCS Code For First Trimester Single Fetus: Procedure Code Group Overview

BY4B-FIRST-TRIMESTER-MULTIPLE-GESTATION-ULTRASONOGRAPHY

ICD-10-PCS Code For First Trimester, Multiple Gestation: Procedure Code Group Overview

BY4D-SECOND-TRIMESTER-MULTIPLE-GESTATION-ULTRASONOGRAPHY

ICD-10-PCS Code For Second Trimester, Multiple Gestation: Procedure Code Group Overview

BY4F-THIRD-TRIMESTER-SINGLE-FETUS-ULTRASONOGRAPHY

ICD-10-PCS Code For Third Trimester Single Fetus: Procedure Code Group Overview

BY4G-THIRD-TRIMESTER-MULTIPLE-GESTATION-ULTRASONOGRAPHY

ICD-10-PCS Code For Third Trimester, Multiple Gestation: Procedure Code Group Overview

Frequently Asked Questions

References

1.CPT® Codes and Descriptions. AAPC. Retrieved Aug 11, 2026.Maintains the CPT code set's official descriptions and guidelines, licensed from the American Medical Association, used as the definitional source for CPT codes on this page.
2.HCPCS Quarterly Update. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's quarterly release of HCPCS Level II codes and short/long descriptors, the source for HCPCS code definitions and update history.
3.ICD-10-CM Full Code List. Centers for Medicare & Medicaid Services (CMS). Retrieved Aug 11, 2026.CMS's complete ICD-10-CM diagnosis code list, used to cross-reference diagnosis codes associated with this procedure or service.

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ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview

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Second Trimester, Single Fetus Ultrasonography Procedure Overview

Code Attributes

OpenPayer

ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview

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Second Trimester, Single Fetus Ultrasonography Procedure Overview

Code Attributes

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

References

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

References

ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview

Sign up for ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview policy alerts

Second Trimester, Single Fetus Ultrasonography Procedure Overview

Code Attributes

ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview

Sign up for ICD-10-PCS Code For Second Trimester, Single Fetus: Procedure Code Group Overview policy alerts

Second Trimester, Single Fetus Ultrasonography Procedure Overview

Code Attributes

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

Which procedures are included in the BY4C code group?

What is the title for the ICD-10-PCS group BY4C?

When should `BY4CZZZ` be used in inpatient documentation?

What are the code attributes for this procedure group?

Are there related DRGs listed for BY4C?

References

When to Use

ICD-10-PCS Codes

Typical Clinical Scenarios

Related Codes

Which procedures are included in the BY4C code group?

What is the title for the ICD-10-PCS group BY4C?

When should `BY4CZZZ` be used in inpatient documentation?

What are the code attributes for this procedure group?

Are there related DRGs listed for BY4C?

References