- Li-Fraumeni cancer syndrome V84.01
- Liar, pathologic 301.7
- Libman-Sacks disease or syndrome 710.0 [424.91]
- Lice (infestation) 132.9
- Lichen 697.9
- Lichenification 698.3
- Lichenoides tuberculosis (primary) (see also Tuberculosis) 017.0
- Lichtheim's disease or syndrome (subacute combined sclerosis with pernicious anemia) 281.0 [336.2]
- Lien migrans 289.59
- Lientery (see also Diarrhea) 787.91
- Life circumstance problem NEC V62.89
- Ligament - see condition
- Light-for-dates (infant) 764.0
- Light-headedness 780.4
- Lightning (effects) (shock) (stroke) (struck by) 994.0
- Lightwood's disease or syndrome (renal tubular acidosis) 588.89
- Lignac (-de Toni) (-Fanconi) (-Debré) syndrome (cystinosis) 270.0
- Lignac (-Fanconi) syndrome (cystinosis) 270.0
- Lignac's disease (cystinosis) 270.0
- Ligneous thyroiditis 245.3
- Likoff's syndrome (angina in menopausal women) 413.9
- Limb - see condition