ZIP Code 20877 — Gaithersburg city, MD Demographics & Data

ZIP code 20877 covers Gaithersburg, MD in Montgomery County with a population of about 39,068.

At a glance, the area shows median age of 37.2 versus a U.S. median of about 38.9.

It sits in telephone area codes 227, 240, 301; U.S. House district MD-6; the WASHINGTON, DC (HAGRSTWN) media market.

Median household income in ZIP 20877 is about $86,103 — about 15% above the U.S. median ($75,149).

On socioeconomic markers, US5 shows a poverty rate of 11.3%; unemployment rate near 6.2%; 35.2% of adults with a bachelor’s degree or higher (about 1.5 points above the national share (33.7%)).

Labor and commute patterns include leading industry context around Construction, Healthcare, and Food services; about 15.9% of workers reporting work-from-home (roughly in line with 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 $462,500 — about 33% above the U.S. median home value ($348,079).

Housing tenure and rents show median gross rent around $1,729 (about 49% above the U.S. median rent ($1,163)), and owner-occupancy near 43.9% (about 21.5 points below the national owner-occupancy rate (65.4%)).

To comfortably buy a median-priced home in ZIP 20877 in Gaithersburg, MD, a household would need roughly $127,000 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 $2,971. That is about 47% above the local median household income ($86,103), so the median earner would likely stretch or need a larger down payment. 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 Gaithersburg city, MD as Relatively Moderate (composite score 91.7), which is among the highest nationally. The strongest component scores on US5 are flood (93.7) and hurricane (91.8). 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 Gaithersburg city, MD show little to no average snow and around 41.3 inches of annual precipitation.

IRS migration statistics show a net inflow of about 2,295 for ZIP 20877 (Gaithersburg city, 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.