ICD-10 Code A51.44 – Secondary syphilitic nephritis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A51.44 – Secondary syphilitic nephritis
What it is
A51.44 identifies kidney inflammation caused by secondary syphilis. Use it when documentation links nephritis to active secondary syphilitic infection rather than another renal condition.
Clinical signs
Clinical features vary; refer to documentation. Records may note renal involvement in the setting of secondary syphilis, such as proteinuria or other signs of nephritic disease, but the syphilis link must be clear.
When to use this code
Use this code when the provider documents secondary syphilis with nephritis or syphilitic renal involvement. It is appropriate when the kidney disorder is attributed to the secondary stage of syphilis, not merely concurrent infection.
If the chart only says syphilis or kidney disease without a causal connection, check documentation before coding. You should also verify whether another diagnosis better explains the renal findings.
Do not use for
Do not use for nonspecific nephritis, chronic kidney disease, or renal disease from other causes. Do not assign it when syphilis is historical, suspected, or not documented as the cause.
Coding tip
Look for explicit provider wording connecting secondary syphilis to nephritis before assigning A51.44.