There are currently 16 Interstate Highways that exist entirely or partially in the U.S. state of Maryland.

The shortest primary interstate in Maryland is I-81 at 12.08 mi (19.44 km).

The longest auxiliary interstate in Maryland is I-695 at 51.48 mi (82.85 km).

Maryland has one unsigned interstate, I-595; that highway is marked as U.S. Route 50 and US 301, which are concurrent with I-595 for its entire length.

Maryland has three former interstates which are shaded in dark gray in the list.