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ICD-10-CM 2027 diagnosis code

A51.3Secondary syphilis of skin and mucous membranes

Not billable — use a more specific code

A51.3 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it.

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 A51.3

A51.3 is the ICD-10-CM diagnosis code for secondary syphilis of skin and mucous membranes. It belongs to category A51 (early syphilis), block A50-A64 (infections with a predominantly sexual mode of transmission) and chapter 1 (certain infectious and parasitic diseases). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within A51 (early syphilis), A51.3 is specifically for secondary syphilis of skin and mucous membranes. Related codes cover primary genital syphilis (A51.0), primary anal syphilis (A51.1), primary syphilis of other sites (A51.2), other secondary syphilis (A51.4), latent (A51.5) and unspecified (A51.9).

To report this condition, pick the subcode that matches the documentation: A51.31 (latum), A51.32 (alopecia) and A51.39 (skin).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under A51.3

Notes that apply from higher levels

Instructions written at a parent level also apply to A51.3.

Broader instructions also apply from A50-A64 Infections with a predominantly sexual mode of transmission and Chapter 1: Certain infectious and parasitic diseases.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about A51.3

Is A51.3 billable?

No. A51.3 is a header code. Report one of its more specific subcodes instead.