| A65 | Nonvenereal syphilis |
| A66 | Yaws |
| A66.0 | Initial lesions of yaws |
| A66.1 | Multiple papillomata and wet crab yaws |
| A66.2 | Other early skin lesions of yaws |
| A66.3 | Hyperkeratosis of yaws |
| A66.4 | Gummata and ulcers of yaws |
| A66.5 | Gangosa |
| A66.6 | Bone and joint lesions of yaws |
| A66.7 | Other manifestations of yaws |
| A66.8 | Latent yaws |
| A66.9 | Yaws, unspecified |
| A67 | Pinta [carate] |
| A67.0 | Primary lesions of pinta |
| A67.1 | Intermediate lesions of pinta |
| A67.2 | Late lesions of pinta |
| A67.3 | Mixed lesions of pinta |
| A67.9 | Pinta, unspecified |
| A68 | Relapsing fevers |
| A68.0 | Louse-borne relapsing fever |
| A68.1 | Tick-borne relapsing fever |
| A68.9 | Relapsing fever, unspecified |
| A69 | Other spirochetal infections |
| A69.0 | Necrotizing ulcerative stomatitis |
| A69.1 | Other Vincent's infections |
| A69.2 | Lyme disease |
| A69.20 | Lyme disease, unspecified |
| A69.21 | Meningitis due to Lyme disease |
| A69.22 | Other neurologic disorders in Lyme disease |
| A69.23 | Arthritis due to Lyme disease |
| A69.29 | Other conditions associated with Lyme disease |
| A69.8 | Other specified spirochetal infections |
| A69.9 | Spirochetal infection, unspecified |