Bormio is easy to reach by car.
From Milan or Lake Como, take the SS 38 road from the north end of the lake.
From Bergamo or Brescia, the easiest route is via the Aprica Pass on the SS 39. This road is also open in winter. Or you could travel via the Gavia pass (closed in winter).
From the east, you have the option of the Stelvio pass (only open in summer) or the Gallo pass from Livigno (open all year round) via the Munt La Schlera tunnel in Switzerland. Another option from Switzerland is to take the Bernina pass.
By Train & Bus
The nearest railway station to Bormio is Tirano, reachable from the Milano Centrale railway station in about 2 hours and a half. From Tirano, the bus service run by Perego will take you to the centre of Bormio. You can also find the Perego bus timetable on Google Maps, in the directions section, by clicking on 'public transport'.
The nearest Italian airports are Bergamo and Milan, while Zurich airport is also well served.