- Western Terminus:
- Old Wye Mills Road (MD 662) in Wye Mills
- Eastern Terminus:
- Seashore Highway (DE 404) at the Maryland-Delaware state line
- 24.61 miles
- Talbot, Queen Anne's, Caroline
MD 404 is a major east/west route on the Eastern Shore of Maryland. It begins at Old Wye Mills Road (MD 662), a short distance west of Ocean Gateway (US 50), and runs west through Queen Anne toward Denton. In that area, it becomes an expressway looping around Denton. After a couple of miles, the expressway ends. MD 404 runs southeast to the border with Delaware, where it becomes Seashore Highway (DE 404). In most areas, it is a two-lane undivided road, although some portions are wider. It is known as Queen Anne's Highway in Talbot and Queen Anne's counties and as Shore Highway in Caroline County.
MD 404 has an alternate route along Old Queen Anne's Highway, Main Street, and Hillsboro Road through Queen Anne and Hillsboro. It also has a business route through Denton.