ZIP Code 20899 — Gaithersburg city, MD Demographics & Data

ZIP code 20899 covers Gaithersburg, MD in Montgomery County with a population of about 106.

At a glance, the area shows median age of 70.4 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.

Gaithersburg, MD fits a retirement-oriented profile (high share of residents 65+ (53.8%)). Residents and relocators commonly research healthcare access, everyday amenities (dining, personal services), and housing costs rather than tech or campus life.

Median household income in ZIP 20899 is about $23,917 — about 68% below the U.S. median ($75,149).

On socioeconomic markers, US5 shows a poverty rate of 17.0%; unemployment rate near 56.3%; 33.0% of adults with a bachelor’s degree or higher (roughly in line with the national share (33.7%)).

Labor and commute patterns include leading industry context around Healthcare; a mean commute of about 14.0 minutes (U.S. average near 26.8).

Housing tenure and rents show median gross rent around $835 (about 28% below the U.S. median rent ($1,163)), and owner-occupancy near 0.0% (about 65.4 points below the national owner-occupancy rate (65.4%)).

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 6 for ZIP 20899 (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.