With abluminal side of a stent masked, the luminal side of the stent is selectively coated with a substance, such as an anti-coagulant, a platelet inhibitor and/or a pro-healing substance. The stent can be masked by inserting it into a rigid mandrel chamber or by compressing a masking sleeve onto the outer side of the stent. A spray nozzle inserted into the masked stent spray coats the substance onto the luminal side. The sprayed coating can be cured onto the stent such as by inserting an electrical-resistance heater bar into the stent.