St. Mary's ZIP codes — St. Mary's County, Maryland

St. Mary's County is a mid-size city in Maryland, with 114,372 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates. The median age here is 37 years against 39.1 nationally, a slightly younger profile than the country as a whole. At this size the Census also publishes one-year estimates; the five-year values used here are steadier and let you compare against smaller neighbours on the same basis.

Households in St. Mary's County earn a median of $114,580 a year, 45.9% above the national figure of $78,538. The median is the midpoint household, not an average, so a handful of very high earners cannot drag it upward the way they distort a mean. Poverty reaches 7.4% of residents here, below the 12.4% national rate.

The typical owner-occupied home in St. Mary's County is valued at $390,900, 28.8% above the national figure, while median gross rent runs $1,692 a month, 20.3% above the national figure, or roughly $20,304 across a full year. A household on the local median income would put about 17.7% of gross pay toward that rent against the federal 30% cost-burden threshold, so renting here is cheap relative to what people here earn. The home-price-to-income ratio works out to 3.4×, against roughly 3.9× nationally, so buying is easier here than in the average US market. 72.6% of occupied homes are owner-occupied versus 65% nationally, so the market leans toward owners. Gross rent folds in the utilities a tenant pays separately, so it is closer to the real monthly outlay than a headline rent figure.

Every value on this page is published directly by the Census for this area — nothing is modelled or interpolated. Small-area estimates still carry wider margins of error than state or national figures, so check the linked ACS tables before relying on them for lending, appraisal or legal work.