A50.9 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupA50.9

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)

A50.9

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

Congenital syphilis, unspecified

This code describes syphilis that was passed from a mother to her baby during pregnancy or birth, but the specific type or manifestation is not documented. Congenital syphilis can affect multiple body systems including the skin, bones, eyes, and nervous system.

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 A50.9Congenital syphilis, unspecified

Inclusion Terms

Official

No inclusion terms are included in this display for A50.9. Check the code and parent instructions in the Code Book.

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 A50.1Early congenital syphilis, latent A50.2Early congenital syphilis, unspecified A50.3Late congenital syphilitic oculopathy A50.4Late congenital neurosyphilis [juvenile neurosyphilis]

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 A50.9. 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 A50.9. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Use this code only when the documentation confirms congenital syphilis but does not specify the particular manifestation (such as early congenital syphilis, late congenital syphilis, or specific organ involvement); if manifestations are documented, use more specific A50 codes (A50.0-A50.7)

Verify that the syphilis is truly congenital (acquired in utero or during birth) rather than acquired syphilis; congenital cases typically appear in newborn or pediatric records with maternal syphilis history

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 A50.9 an HCC code?

No. A50.9 is a billable ICD-10-CM code with no mapping under the current CMS-HCC V28 community payment model, and none under the ESRD, Part D RxHCC, or HHS-HCC models.

Code: A50.9
Description: Congenital syphilis, unspecified
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

Coder workflow notes

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What This Code Means

A50.9 is the ICD-10-CM diagnosis code for congenital syphilis, unspecified. This code describes syphilis that was passed from a mother to her baby during pregnancy or birth, but the specific type or manifestation is not documented. Congenital syphilis can affect multiple body systems including the skin, bones, eyes, and nervous system. A50.9 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).

A50.9 is a billable ICD-10-CM code, but no current CMS-HCC V28 community payment mapping is shown, 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.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for A50.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the documentation confirms congenital syphilis but does not specify the particular manifestation (such as early congenital syphilis, late congenital syphilis, or specific organ involvement); if manifestations are documented, use more specific A50 codes (A50.0-A50.7)
•Verify that the syphilis is truly congenital (acquired in utero or during birth) rather than acquired syphilis; congenital cases typically appear in newborn or pediatric records with maternal syphilis history