| late congenital syphilitic arthropathy | A50.55 |
| late congenital syphilitic chorioretinitis | A50.32 |
| late congenital syphilitic encephalitis | A50.42 |
| late congenital syphilitic interstitial keratitis | A50.31 |
| late congenital syphilitic meningitis | A50.41 |
| late congenital syphilitic optic nerve atrophy | A50.44 |
| late congenital syphilitic osteochondropathy | A50.56 |
| late congenital syphilitic polyneuropathy | A50.43 |
| late lesions of pinta | A67.2 |
| late syphilis | A52 |
| late syphilis, latent | A52.8 |
| late syphilis, unspecified | A52.9 |
| late syphilitic encephalitis | A52.14 |
| late syphilitic meningitis | A52.13 |
| late syphilitic neuropathy | A52.15 |
| late syphilitic oculopathy | A52.71 |
| latent syphilis, unspecified as early or late | A53.0 |
| latent yaws | A66.8 |
| legionnaires' disease | A48.1 |
| leishmaniasis | B55 |
| leishmaniasis, unspecified | B55.9 |
| lentivirus as the cause of diseases classified elsewhere | B97.31 |
| lepromatous leprosy | A30.5 |
| leprosy [hansen's disease] | A30 |
| leprosy, unspecified | A30.9 |
| leptospirosis | A27 |
| leptospirosis icterohemorrhagica | A27.0 |
| leptospirosis, unspecified | A27.9 |
| listerial endocarditis | A32.82 |
| listerial meningitis | A32.11 |
| listerial meningoencephalitis | A32.12 |
| listerial sepsis | A32.7 |
| listeriosis | A32 |
| listeriosis, unspecified | A32.9 |
| liver fluke | B88.8.1 |
| lobomycosis | B48.0 |
| localized salmonella infection, unspecified | A02.20 |
| loiasis | B74.3 |
| louse-borne relapsing fever | A68.0 |
| lung fluke | 18.2.5.1 |
| lyme disease | A69.20.1 |
| lymphocutaneous sporotrichosis | B42.1 |
| lymphocytic choriomeningitis | A87.2 |
| machupo hemorrhagic fever | A96.1 |
| malaria due to simian plasmodia | B53.1 |
| mansonelliasis | B74.4 |
| marburg virus disease | A98.3 |
| measles | B05 |
| measles complicated by encephalitis | B05.0 |
| measles complicated by meningitis | B05.1 |
| measles complicated by otitis media | B05.3 |
| measles complicated by pneumonia | B05.2 |
| measles keratitis and keratoconjunctivitis | B05.81 |
| measles with intestinal complications | B05.4 |
| measles without complication | B05.9 |
| megacolon in chagas' disease | B57.32 |
| megaesophagus in chagas' disease | B57.31 |
| melioidosis, unspecified | A24.9 |
| meningeal tuberculoma | A17.1 |
| meningitis due to lyme disease | A69.21 |
| meningitis in chagas' disease | B57.41 |
| meningococcal arthritis | A39.83 |
| meningococcal carditis, unspecified | A39.50 |
| meningococcal encephalitis | A39.81 |
| meningococcal endocarditis | A39.51 |
| meningococcal infection | A39 |
| meningococcal infection, unspecified | A39.9 |
| meningococcal meningitis | A39.0 |
| meningococcal myocarditis | A39.52 |
| meningococcal pericarditis | A39.53 |
| meningococcal retrobulbar neuritis | A39.82 |
| meningococcemia, unspecified | A39.4 |
| meningoencephalitis due to acanthamoeba (culbertsoni) | B60.11 |
| meningoencephalitis in chagas' disease | B57.42 |
| methicillin resistant staphylococcus aureus infection as the cause of diseases classified elsewhere | B95.62 |
| methicillin resistant staphylococcus aureus infection, unspecified site | A49.02 |
| methicillin susceptible staphylococcus aureus infection as the cause of diseases classified elsewhere | B95.61 |
| methicillin susceptible staphylococcus aureus infection, unspecified site | A49.01 |
| miliary tuberculosis | A19 |
| miliary tuberculosis, unspecified | A19.9 |
| mixed intestinal helminthiases | B81.4 |
| mixed lesions of pinta | A67.3 |
| mixed pediculosis and phthiriasis | B85.4 |
| molluscum contagiosum | B08.1 |
| monkeypox | B04 |
| monkeypox | B04 |
| mosquito-borne viral encephalitis | A83 |
| mosquito-borne viral encephalitis, unspecified | A83.9 |
| mosquito-borne viral fever, unspecified | A92.9 |
| mucocutaneous leishmaniasis | B55.2 |
| mucormycosis, unspecified | B46.5 |
| multiple papillomata and wet crab yaws | A66.1 |
| mumps | B26 |
| mumps arthritis | B26.85 |
| mumps encephalitis | B26.2 |
| mumps hepatitis | B26.81 |
| mumps meningitis | B26.1 |
| mumps myocarditis | B26.82 |
| mumps nephritis | B26.83 |
| mumps orchitis | B26.0 |