St. Marys, IA population, income and ZIP codes

St. Marys city is a very small community in Iowa, with 112 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #844 of 1,026 ranked by population — larger than 17% of them. The median age here is 53.5 years against 39.1 nationally, a markedly older profile that usually tracks retirees staying put and younger households leaving for work. At this population the ACS sample is small, so the margin of error around every dollar figure below is wide — treat the numbers as a band, not a point, and expect them to move between annual releases without the place itself changing.

Households in St. Marys city earn a median of $78,750 a year, essentially level with the national figure of $78,538 and 16% above the $67,791 median for the 290 Iowa cities we cover. This figure covers the household, not the worker: two people on ordinary wages at one address outrank a single professional in the same table. Poverty reaches 6.2% of residents here, less than half the 12.4% national rate.

The typical owner-occupied home in St. Marys city is valued at $168,800, 44.4% below the national figure and 8% above the $156,300 peer median, while median gross rent runs $1,300 a month, 7.5% below the national figure, or roughly $15,600 across a full year. A household on the local median income would put about 19.8% 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 2.1×, against roughly 3.9× nationally, so purchase prices are unusually low against local pay, the pattern in places where supply is plentiful and wage growth has been flat. 76.9% of occupied homes are owner-occupied versus 65% nationally, so the market leans toward owners. Rent is reported gross — contract rent plus tenant-paid utilities — which is why it runs above the advertised price on a listing for the same unit.

A median age of 53.5 puts St. Marys city well into retirement-weighted territory, which pulls median household income down even where household wealth is high, because retirement draws are counted differently from wages. With 112 residents, a handful of survey responses moves every median on this page. Compare St. Marys city against its county rather than against national figures.

All values below were released by the Census for this exact geography, with no gap-filling on our side. 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.