The median age in Lee’s Summit is 38.8 years, placing it below the Missouri statewide figure of 39.0 and below Cass County’s 40.4, but above Jackson County’s 37.0. Of the four figures in the data, Cass County is the oldest and Jackson County the youngest; Lee’s Summit falls closer to the middle, near the state benchmark.
Median age shapes the kinds of demands a city places on its own systems. A city with a median age in the high 30s tends to carry a large share of households in the school-age and early-career years — the life stage the city’s own growth story is built around. Lee’s Summit R-7 has been adding capacity for years; the age profile in this data is consistent with a city still absorbing families with children rather than one that has aged past that cycle.
Jackson County, which includes Kansas City proper, posts the lowest median age of the four. Cass County, to the south, posts the highest. Lee’s Summit, which straddles the edge of Jackson County, lands between those two county figures — younger than Cass, older than Jackson County as a whole, and roughly at the state midpoint.
These are 2020–2024 ACS 5-year estimates. Each figure carries a margin of error; the ladder above marks each ±MOE.