ICD-10 Code A52.78 – Syphilis of other musculoskeletal tissue (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A52.78 – Syphilis of other musculoskeletal tissue
What it is
This code identifies syphilis involving musculoskeletal tissue outside the more commonly named sites. It is used when the infection is documented in bone, joint, muscle, or related tissue and no more specific code fits.
Clinical signs
Clinical features vary; refer to documentation. Findings may include localized pain, swelling, tenderness, reduced motion, or other signs of musculoskeletal involvement confirmed by the clinician.
When to use this code
Use A52.78 when the record clearly states syphilis affecting other musculoskeletal tissue and the documentation does not specify a more exact musculoskeletal site. You should code it for confirmed infection, not for suspicion alone. If the note only says musculoskeletal pain without a syphilis diagnosis, check documentation.
Do not use for
Do not use this code for syphilis limited to other named organ systems or for nonspecific musculoskeletal pain without documented syphilitic involvement. Check documentation if the site or diagnosis is unclear.
Coding tip
Confirm both the syphilis diagnosis and the exact musculoskeletal site in the provider note before assigning A52.78.