ICD-10-CM 2027
ICD-10 code for keratitis syphilis
Late congenital syphilitic interstitial keratitis
From the official ICD-10-CM alphabetic index entry “Syphilis, syphilitic (acquired) › keratitis (congenital) (interstitial) (late)”. Page updated September 29, 2026.
About coding keratitis syphilis
The ICD-10-CM code for keratitis syphilis is A50.31 (Late congenital syphilitic interstitial keratitis).
Within A50.3 (late congenital syphilitic oculopathy), A50.31 is specifically for late congenital syphilitic interstitial keratitis. Related codes cover unspecified (A50.30), late congenital syphilitic chorioretinitis (A50.32) and other late congenital syphilitic oculopathy (A50.39).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 124 (Other Disorders of the Eye with MCC or Thrombolytic Agent, relative weight 1.2471) and DRG 125 (Other Disorders of the Eye without MCC, relative weight 0.7702), in MDC 02 (Diseases and Disorders of the Eye), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about keratitis syphilis ICD-10 codes
What is the ICD-10 code for keratitis syphilis?
- A50.31 — Late congenital syphilitic interstitial keratitis.
Is A50.31 billable?
- Yes. A50.31 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A50.31 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A50.31 as a principal diagnosis.
Is A50.31 a CC or MCC?
- A50.31 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.