ZIP Code 21409 — Cape St. Claire CDP, MD Demographics & Data

ZIP code 21409 covers Cape St. Claire, MD in Anne Arundel County with a population of about 20,175.

At a glance, the area shows median age of 42.8 versus a U.S. median of about 38.9.

It sits in telephone area codes 410, 443, 667; U.S. House district MD-3; the BALTIMORE media market.

Cape St. Claire, MD aligns with a tech / corporate-campus profile (high remote-work / education / income profile or known campus context). Broadband quality, remote-work share, and nearby employer campuses often matter as much as classic residential stats.

Median household income in ZIP 21409 is about $146,667 — about 95% above the U.S. median ($75,149).

On socioeconomic markers, US5 shows a poverty rate of 2.5%; unemployment rate near 3.2%; 57.4% of adults with a bachelor’s degree or higher (about 23.7 points above the national share (33.7%)).

Labor and commute patterns include leading industry context around Professional services, Public administration, and Education; about 22.3% of workers reporting work-from-home (about 7.1 points above the U.S. share (15.2%)); a mean commute of about 180.0 minutes (U.S. average near 26.8).

Median home value is about $499,700 — about 44% above the U.S. median home value ($348,079).

Housing tenure and rents show median gross rent around $1,787 (about 54% above the U.S. median rent ($1,163)), and owner-occupancy near 90.4% (about 25.0 points above the national owner-occupancy rate (65.4%)).

To comfortably buy a median-priced home in ZIP 21409 in Cape St. Claire, MD, a household would need roughly $138,000 in annual income under a 20% down, 30-year loan at 6.8% (illustrative), keeping housing costs near 28% of income. Estimated monthly PITI is about $3,210. That is roughly in line with the local median household income ($146,667). Rates, taxes, insurance, and HOA fees vary — treat this as a planning estimate, not a lender quote.

FEMA’s National Risk Index rates natural-hazard risk for Cape St. Claire CDP, MD as Relatively Moderate (composite score 81.9), which is elevated versus much of the country. The strongest component scores on US5 are hurricane (87.2) and flood (80.9). These scores are county-linked NRI values published for planning context — all ZIP codes in the same county share the same composite score on US5. Useful when comparing insurance and disaster exposure across areas, not a substitute for a parcel-level flood or fire determination.

Climate normals for Cape St. Claire CDP, MD show little to no average snow and around 44.0 inches of annual precipitation.

IRS migration statistics show a net inflow of about 1,185 for ZIP 21409 (Cape St. Claire CDP, MD) on US5’s published series — a signal of people/tax filers moving in relative to those leaving. Inflows often track job growth, housing demand, or lifestyle migration; treat the figure as a directional indicator rather than a precise headcount.