A51.44 ICD-10-CM Code: Secondary syphilitic nephritis

A51.44 is the ICD-10-CM diagnosis code for secondary syphilitic nephritis. This is a kidney infection caused by syphilis that develops during the secondary stage of the disease, after the initial infection has spread throughout the body. It occurs when the syphilis bacteria damages the kidney's filtering structures. A51.44 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).

A51.44 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Verify that the patient has documented secondary syphilis with confirmed kidney involvement before assigning this code; do not assume nephritis without clinical evidence.