Preferred Name, USPS. The practice location is 635 Simpson St, Plymouth, MI 48170-2258. Map of ZIP Codes in Plymouth, Michigan. 2016 cost of living index in zip code 55441: 114.7 (more than average, U.S. average is 100) Land area: 8.7 sq. Find MoreCities in Michigan that start with P, Post Office Suburb:PLYMOUTH, MI, 48170-1621,