- Osteogenesis imperfecta 756.51
- Osteogenic - see condition
- Osteoma (M9180/0) - see also Neoplasm, bone, benign
- Osteomalacia 268.2
- Osteomalacic bone 268.2
- Osteomalacosis 268.2
- Osteomyelitis (general) (infective) (localized) (neonatal) (purulent) (pyogenic) (septic) (staphylococcal) (streptococcal) (suppurative) (with periostitis) 730.2
- Osteomyelofibrosis 289.89
- Osteomyelosclerosis 289.89
- Osteonecrosis 733.40
- Osteopathia
- Osteopathy resulting from poliomyelitis (see also Poliomyelitis) 045.9 [730.7]
- Osteopecilia 756.53
- Osteopenia 733.90
- Osteoperiostitis (see also Osteomyelitis) 730.2
- Osteopetrosis (familial) 756.52
- Osteophyte - see Exostosis
- Osteophytosis - see Exostosis
- Osteopoikilosis 756.53
- Osteoporosis (generalized) 733.00
- Osteoporosis-osteomalacia syndrome 268.2
- Osteopsathyrosis 756.51