A51: Early syphilis
Codes under A51 (Early syphilis). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.
| Code | Description | Billable |
|---|---|---|
| A51.0 | Primary genital syphilis | ✓ |
| A51.0 | Primary genital syphilis | ✓ |
| A51.1 | Primary anal syphilis | ✓ |
| A51.1 | Primary anal syphilis | ✓ |
| A51.2 | Primary syphilis of other sites | ✓ |
| A51.2 | Primary syphilis of other sites | ✓ |
| A51.3 | Secondary syphilis of skin and mucous membranes | — |
| A51.3 | Secondary syphilis of skin and mucous membranes | — |
| A51.4 | Other secondary syphilis | — |
| A51.4 | Other secondary syphilis | — |
| A51.5 | Early syphilis, latent | ✓ |
| A51.5 | Early syphilis, latent | ✓ |
| A51.9 | Early syphilis, unspecified | ✓ |
| A51.9 | Early syphilis, unspecified | ✓ |
| A51.31 | Condyloma latum | ✓ |
| A51.31 | Condyloma latum | ✓ |
| A51.32 | Syphilitic alopecia | ✓ |
| A51.32 | Syphilitic alopecia | ✓ |
| A51.39 | Other secondary syphilis of skin | ✓ |
| A51.39 | Other secondary syphilis of skin | ✓ |
| A51.41 | Secondary syphilitic meningitis | ✓ |
| A51.41 | Secondary syphilitic meningitis | ✓ |
| A51.42 | Secondary syphilitic female pelvic disease | ✓ |
| A51.42 | Secondary syphilitic female pelvic disease | ✓ |
| A51.43 | Secondary syphilitic oculopathy | ✓ |
| A51.43 | Secondary syphilitic oculopathy | ✓ |
| A51.44 | Secondary syphilitic nephritis | ✓ |
| A51.44 | Secondary syphilitic nephritis | ✓ |
| A51.45 | Secondary syphilitic hepatitis | ✓ |
| A51.45 | Secondary syphilitic hepatitis | ✓ |
| A51.46 | Secondary syphilitic osteopathy | ✓ |
| A51.46 | Secondary syphilitic osteopathy | ✓ |
| A51.49 | Other secondary syphilitic conditions | ✓ |
| A51.49 | Other secondary syphilitic conditions | ✓ |
Frequently asked questions
What is ICD-10-CM code A51?
A51 is an ICD-10-CM category covering Early syphilis. It contains 34 more specific diagnosis codes, 30 of which are billable.
Is A51 a billable code?
No — A51 is a category header and isn't billable on its own. Code to the highest level of specificity using one of its subcodes (for example A51.0 — Primary genital syphilis). 30 of the 34 codes under A51 are billable.
What codes fall under A51?
A51 includes A51.0, A51.0, A51.1, A51.1, A51.2, plus 29 more. See the full list with descriptions and billable status above.
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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
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