It travels 9 miles (14 km) from north to south, connecting the northern Seattle suburbs of Bothell, Mill Creek, and Everett.

During the 1990s and early 2000s, the state government funded several projects that widened the highway to its present four-lane configuration with sidewalks, bus pullouts, and bicycle lanes.

SR 527 begins as a continuation of the Bothell–Everett Highway at a partial cloverleaf interchange with I-405 in northern Bothell, located in Snohomish County.

[6][7] Near Henry M. Jackson High School, the highway turns northeast and intersects SR 96 at Murphy's Corner, located at the southern city limit of Everett.

The highway briefly travels west along the northeast shore of the lake before turning sharply to the north onto 19th Avenue Southeast and passes through a commercial district while remaining parallel to I-5.

[14][15] An early wagon road along North Creek between Bothell and Lowell (now part of Everett) was built in the late 19th century by local settlers and the county government.

[19] The Bothell–Everett portion of the highway was paved with concrete in 1916, following a bond issue for improved roads approved by Snohomish County voters the year prior.

[19][36] The state legislature funded the widening project in 1990 with proceeds from a statewide gas tax increase, which coincided with the end of the development moratorium.

[38] Construction of the second phase, between Thrashers Corner and 164th Street in Mill Creek, was delayed by concerns that stormwater runoff would be inadequately handled by the new road.

[44] The two-year project included the construction of barriers, culverts, and detention ponds along the shore of Silver Lake, which also gained a pedestrian walkway with interpretive signs.

[44][45] In 2009, the City of Bothell adopted plans to convert the southernmost blocks of SR 527 into a mixed-use boulevard and submitted a request to transfer a section of the highway from the state's control.