An exhaust-gas turbocharger for an internal combustion engine has a turbine housing, in which a turbine wheel with a shaft is arranged rotatably. The shaft is mounted rotatably in a bearing housing via at least one piston ring adjacently with respect to the turbine wheel. The bearing housing has a lubricant inflow and a pressureless lubricant outflow for lubricating the shaft, wherein an insulating washer is provided which is clamped in by the turbine housing and the bearing housing and has an opening which is connected to the lubricant outflow in a manner which conducts a lubricant. Passage of lubricant out of the bearing housing into the turbine housing is avoided.