ICD-10-CM 2027 diagnosis code
A50.1Early congenital syphilis, latent
A50.1 is a valid, billable ICD-10-CM code for early congenital syphilis, latent. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About A50.1
A50.1 is the ICD-10-CM diagnosis code for early congenital syphilis, latent. It belongs to category A50 (congenital syphilis), block A50-A64 (infections with a predominantly sexual mode of transmission) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
Within A50 (congenital syphilis), A50.1 is specifically for early congenital syphilis, latent. Related codes cover early congenital syphilis, symptomatic (A50.0), early congenital syphilis, unspecified (A50.2), late congenital syphilitic oculopathy (A50.3), late congenital neurosyphilis [juvenile neurosyphilis] (A50.4), other late congenital syphilis, symptomatic (A50.5), late congenital syphilis, latent (A50.6), late congenital syphilis, unspecified (A50.7) and unspecified (A50.9).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 090.1 (early congenital syphilis, latent).
Coding notes
- Congenital syphilis without clinical manifestations, with positive serological reaction and negative spinal fluid test, less than two years after birth.
Notes that apply from higher levels
Instructions written at a parent level also apply to A50.1.
Broader instructions also apply from A50-A64 Infections with a predominantly sexual mode of transmission and Chapter 1: Certain infectious and parasitic diseases.
Alphabetic index entries
3 entriesTerms in the official ICD-10-CM index that lead to A50.1.
- Syphilis, syphilitic (acquired) › congenital › early, or less than 2 years after birth NEC › latent (without manifestations)
- Syphilis, syphilitic (acquired) › congenital › early, or less than 2 years after birth NEC › latent (without manifestations) › negative spinal fluid test
- Syphilis, syphilitic (acquired) › congenital › early, or less than 2 years after birth NEC › latent (without manifestations) › serology positive
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 18 · Infectious and Parasitic Diseases, Systemic or Unspecified Sites
ICD-9-CM equivalent
Converter →- 090.1Early congenital syphilis, latentexact
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about A50.1
Is A50.1 billable?
- Yes. A50.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A50.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A50.1 as a principal diagnosis.
Is A50.1 a CC or MCC?
- No. A50.1 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does A50.1 group to?
- A50.1 is used in the MS-DRG v44.0 logic for MS-DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC), MS-DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC) and MS-DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.
What is the ICD-9 code for A50.1?
- The CMS General Equivalence Mappings map A50.1 to ICD-9-CM 090.1.