The eastern section terminates at both ends at US 150 in Martin County between Loogootee and Lacy.

The western segment of SR 550 begins at an intersection with US 41/US 150.

SR 550 heads southeast towards Wheatland passing through an intersection with State Road 67 in Bruceville.

SR 550 enters Wheatland on the northwest side of town and heads towards its eastern terminus of this section at an intersection with US 50/US 150[2] The eastern section of SR 550 begins in Loogootee, east of the US 50/US 150/U.S.

SR 550 heads southeast then turning east.