The number plate light on a Subaru Outback is located in a small recessed area on the rear hatch, directly above the rear number plate. This light illuminates when the headlamps are turned on in order to make the rear number plate visible in lowlight and nighttime conditions. When the number plate light burns out, the rear number plate will not be visible to law enforcement vehicles, which can get you ticketed and fined. You can replace an Outback's number plate bulb yourself. Replacement bulbs are available from auto parts and hardware stores.
Place the Outback's transmission in "Park" (or first gear if it has a manual transmission) and shut off the engine. Apply the parking brake.
Look inside the recessed area above the number plate and notice the number plate bulb. Reach inside this area and grip the bulb between your thumb and index finger. Pull the bulb to the right in order to free it from its electrical socket. Discard the old bulb.
Install the new bulb in the socket. Turn on the headlamps and verify that the number plate lamp is illuminated.