What is ICD-10 code A50.1?

A50.1 is the ICD-10-CM diagnosis code for Early congenital syphilis, latent. It belongs to the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99). A50.1 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. A50.1 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. A50.1 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. A50.1 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does A50.1 map to under V28?

A50.1 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for A50.1?

A50.1 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for A50.1?

A50.1 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

2026 ICD-10-CM A50.1: Early congenital syphilis, latent

A50.1 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools

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Code lookupA50.1

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Infections with a predominantly sexual mode of transmission (A50-A64)

A50.1

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Early congenital syphilis, latent

This is a condition where a baby was infected with syphilis before birth from their mother, but the infection is in a hidden or dormant stage without active symptoms showing. The infection is present in the body but not currently causing visible signs of disease.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

A50Congenital syphilis A50.1Early congenital syphilis, latent

Inclusion Terms

Official

Congenital syphilis without clinical manifestations, with positive serological reaction and negative spinal fluid test, less than two years after birth.

Excludes 2

Official

carrier or suspected carrier of infectious disease (Z22.-)Inherited from A00-B99, A50-A64
infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)Inherited from A00-B99, A50-A64
infectious and parasitic diseases specific to the perinatal period (P35-P39)Inherited from A00-B99, A50-A64
influenza and other acute respiratory infections (J00-J22)Inherited from A00-B99, A50-A64
human immunodeficiency virus [HIV] disease (B20)Inherited from A00-B99, A50-A64

Related Codes

Official

A50.0Early congenital syphilis, symptomatic A50.2Early congenital syphilis, unspecified A50.3Late congenital syphilitic oculopathy A50.4Late congenital neurosyphilis [juvenile neurosyphilis]A50.5Other late congenital syphilis, symptomatic

Includes

Official

diseases generally recognized as communicable or transmissibleInherited from A00-B99

Excludes 1

Official

certain localized infections - see body system-related chaptersInherited from A00-B99, A50-A64
nonspecific and nongonococcal urethritis (N34.1)Inherited from A00-B99, A50-A64
Reiter's disease (M02.3-)Inherited from A00-B99, A50-A64

Code First

Official

No Code First sequencing instructions are included in this display for A50.1. Check the code and parent instructions in the Code Book.

Use Additional

Official

code to identify resistance to antimicrobial drugs (Z16.-)Inherited from A00-B99

Code Also

Official

No Code Also instructions are included in this display for A50.1. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

This code is used specifically for congenital syphilis cases that are in the latent (asymptomatic) phase; do not use this code if the patient is showing active symptoms of early congenital syphilis

Always verify the patient's age and confirm maternal syphilis history in the medical record, as this diagnosis applies only to infants and young children with documented congenital transmission

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is A50.1 an HCC code?

No. A50.1 is a billable ICD-10-CM code with no mapping under the CMS-HCC V28 or V24 community payment models, and none under the ESRD, Part D RxHCC, or HHS-HCC models.

Code: A50.1
Description: Early congenital syphilis, latent
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

Coder workflow notes

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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

A50.1 is the ICD-10-CM diagnosis code for early congenital syphilis, latent. This is a condition where a baby was infected with syphilis before birth from their mother, but the infection is in a hidden or dormant stage without active symptoms showing. The infection is present in the body but not currently causing visible signs of disease. A50.1 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering infections with a predominantly sexual mode of transmission (a50-a64).

A50.1 is a billable ICD-10-CM code, but the current payload does not show a mapping under the CMS-HCC V28 or V24 community payment models, and none under the ESRD, Part D RxHCC, or HHS-HCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.

This code is used specifically for congenital syphilis cases that are in the latent (asymptomatic) phase; do not use this code if the patient is showing active symptoms of early congenital syphilis.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for A50.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This code is used specifically for congenital syphilis cases that are in the latent (asymptomatic) phase; do not use this code if the patient is showing active symptoms of early congenital syphilis
•Always verify the patient's age and confirm maternal syphilis history in the medical record, as this diagnosis applies only to infants and young children with documented congenital transmission