Mountlake Terrace, Washington demographics

Mountlake Terrace, WA demographics: median age 38.3; 43.0% of adults 25+ hold a bachelor’s degree. Age, race, households, languages and education, ACS 2020–2024 with margins of error.

ACS 2020–2024 · Mountlake Terrace city, Washington · Incorporated city · GEOID 5347490. The survey estimates a population of 23,104 for its five-year window. This is separate from the annual July 2025 population estimate on the city overview.

Median age in Mountlake Terrace is 38.3 years, with a 90% margin of error of 1.3 years. There are 9,855 households (±382). Age and household distributions show how these totals are composed; they do not establish which neighborhood suits a particular person.

Every count and share is an estimate. “±” is a 90% margin of error (MOE); pp means percentage points. Derived shares use the category count divided by the named universe. Aggregated category MOEs and percentage MOEs are approximate. A margin larger than half its estimate is flagged as low precision. Blank source uncertainty is shown as unavailable, never zero.

Age distribution and sex

City, state and U.S. estimates · ACS 2020–2024
Measure / survey universe	City estimate ± MOE	State estimate ± MOE	U.S. estimate ± MOE
Median age Total population · years	38.3 ±1.3	38.3 ±0.1	38.9 ±0.1

Age groups · B01001 · ACS 2020–2024 Total population: 23,104
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Under 18	3,919 ±506	17.0% ±2.2 pp	21.4%	22.0%
18–34	6,043 ±636	26.2% ±2.8 pp	23.7%	22.8%
35–64	9,332 ±719	40.4% ±3.1 pp	38.3%	38.0%
65 and older	3,810 ±414	16.5% ±1.8 pp	16.6%	17.2%

Sex categories as published by ACS · B01001 · ACS 2020–2024 Total population: 23,104
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Male	11,426 ±409	49.5% ±1.8 pp	50.4%	49.5%
Female	11,678 ±413	50.5% ±1.8 pp	49.6%	50.5%

The age groups are mutually exclusive and cover the entire population. The sex categories follow this ACS table’s published classification; they are not a survey of gender identity.

Race and Hispanic origin

Race · B02001 · ACS 2020–2024 Total population: 23,104
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
White alone	14,222 ±791	61.6% ±3.4 pp	65.8%	61.0%
Black or African American alone	970 ±302	4.2% ±1.3 pp	4.0%	12.2%
American Indian and Alaska Native alone	220 ±164 · low precision	1.0% ±0.7 pp · low precision	1.2%	0.9%
Asian alone	2,667 ±430	11.5% ±1.9 pp	9.8%	6.0%
Native Hawaiian and Other Pacific Islander alone	74 ±80 · low precision	0.3% ±0.3 pp · low precision	0.7%	0.2%
Some other race alone	1,925 ±651	8.3% ±2.8 pp	5.8%	7.1%
Two or more races	3,026 ±541	13.1% ±2.3 pp	12.8%	12.6%

Hispanic or Latino origin · B03003 · ACS 2020–2024 Total population: 23,104
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Not Hispanic or Latino	19,580 ±678	84.7% ±2.9 pp	85.6%	80.7%
Hispanic or Latino	3,524 ±684	15.3% ±3.0 pp	14.4%	19.3%

Hispanic origin and race are separate questions. People of Hispanic or Latino origin may be of any race and appear in both tables. Do not add the Hispanic share to race shares. Race alone and two-or-more-race groups are the mutually exclusive categories of the race table.

Household types, children and living alone

Household types · B11001 · ACS 2020–2024 Households: 9,855
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Married-couple family	4,124 ±349	41.8% ±3.1 pp	49.1%	46.9%
Other family: male householder, no spouse present	707 ±209	7.2% ±2.1 pp	4.8%	5.1%
Other family: female householder, no spouse present	822 ±251	8.3% ±2.5 pp	9.5%	12.2%
Nonfamily: householder living alone	2,988 ±414	30.3% ±4.0 pp	27.7%	28.7%
Nonfamily: householder not living alone	1,214 ±273	12.3% ±2.7 pp	8.9%	7.0%

Households with children · B11005 · ACS 2020–2024 Households: 9,855
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Households with people under 18	2,398 ±238	24.3% ±2.2 pp	29.3%	29.5%
Households without people under 18	7,457 ±510	75.7% ±4.3 pp	70.7%	70.5%

Household size · B11016 · ACS 2020–2024 Households: 9,855
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
One-person nonfamily households	2,988 ±414	30.3% ±4.0 pp	27.7%	28.7%
Two-person households	3,791 ±435	38.5% ±4.2 pp	35.3%	33.8%
Three-person households	1,302 ±273	13.2% ±2.7 pp	15.1%	15.3%
Four-person households	1,282 ±228	13.0% ±2.3 pp	12.7%	12.6%
Five-person households	342 ±133	3.5% ±1.3 pp	5.6%	5.9%
Six-person households	92 ±55 · low precision	0.9% ±0.6 pp · low precision	2.2%	2.2%
Seven or more people	58 ±46 · low precision	0.6% ±0.5 pp · low precision	1.5%	1.4%

A family household contains related people under the Census definition. A nonfamily household can contain one person or unrelated people sharing a home. Households with children can also appear in the household-type and size tables, so those tables must not be added together. Household estimates exclude people living in group quarters from the household universe.

Nativity and languages spoken at home

Nativity · B05002 · ACS 2020–2024 Total population: 23,104
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Native	18,830 ±557	81.5% ±2.4 pp	84.6%	85.9%
Foreign born	4,274 ±561	18.5% ±2.4 pp	15.4%	14.1%

Language spoken at home · C16001 · ACS 2020–2024 Population age 5 and older: 22,160
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
English only	16,959 ±738	76.5% ±3.2 pp	78.6%	77.7%
Spanish	2,293 ±647	10.3% ±2.9 pp	9.0%	13.6%
French, Haitian, or Cajun	20 ±23 · low precision	0.1% ±0.1 pp · low precision	0.4%	0.7%
German or other West Germanic	62 ±51 · low precision	0.3% ±0.2 pp · low precision	0.4%	0.5%
Russian, Polish, or other Slavic	291 ±135	1.3% ±0.6 pp	1.5%	0.7%
Other Indo-European	374 ±166	1.7% ±0.7 pp	2.0%	2.0%
Korean	269 ±167 · low precision	1.2% ±0.8 pp · low precision	0.7%	0.3%
Chinese, including Mandarin and Cantonese	264 ±133 · low precision	1.2% ±0.6 pp · low precision	1.9%	1.1%
Vietnamese	283 ±283 · low precision	1.3% ±1.3 pp · low precision	1.0%	0.5%
Tagalog, including Filipino	387 ±176	1.7% ±0.8 pp	0.9%	0.6%
Other Asian and Pacific Island	448 ±190	2.0% ±0.9 pp	2.1%	1.1%
Arabic	109 ±165 · low precision	0.5% ±0.7 pp · low precision	0.4%	0.5%
Other and unspecified	401 ±223 · low precision	1.8% ±1.0 pp · low precision	1.1%	0.8%

Foreign born means not a U.S. citizen at birth; it includes naturalized citizens. Language categories describe speech at home among people age five and older. A language other than English at home does not establish that someone cannot speak English. This city page uses the published C16001 summary categories because the more detailed B16001 table does not provide these city records in this release.

Educational attainment

Highest completed education · B15003 · ACS 2020–2024 Population age 25 and older: 17,563
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Less than high school graduate	997 ±274	5.7% ±1.5 pp	7.7%	10.4%
High school graduate or equivalency	3,770 ±378	21.5% ±2.0 pp	21.6%	26.0%
Some college, no degree	3,287 ±410	18.7% ±2.3 pp	21.0%	19.1%
Associate’s degree	1,961 ±329	11.2% ±1.8 pp	10.0%	8.8%
Bachelor’s degree	4,939 ±501	28.1% ±2.7 pp	24.0%	21.6%
Graduate or professional degree	2,609 ±377	14.9% ±2.1 pp	15.6%	14.1%

The denominator excludes residents under 25. Each person is counted in the highest attainment category they completed. This table does not measure the quality of local schools or the education level of every current student.

Residence one year earlier

Geographic mobility · B07003 · ACS 2020–2024 Population age 1 and older: 22,963
Category	Count ± MOE	Share ± MOE (pp)	Washington	U.S.
Same house	19,080 ±685	83.1% ±3.0 pp	85.5%	87.7%
Moved within same county	1,705 ±566	7.4% ±2.5 pp	8.0%	6.3%
Moved from a different county in the same state	1,256 ±379	5.5% ±1.7 pp	2.8%	3.1%
Moved from a different state	815 ±366	3.5% ±1.6 pp	2.9%	2.3%
Moved from abroad	107 ±109 · low precision	0.5% ±0.5 pp · low precision	0.8%	0.6%

These are respondents’ residence patterns one year before their survey response, pooled across the five-year window. They are not a net migration count for 2025. A person can move to a different house within the same city or county; moves within the same county should not automatically be interpreted as new arrivals to the city.

Health insurance, internet access and veterans

7.1% of Mountlake Terrace residents (±1.8 percentage points) had no health insurance coverage when surveyed, compared with 6.3% in Washington and 8.4% nationally. 93.5% of households subscribe to broadband of any type, including cellular data plans. A subscription is not the same as available service: the FCC National Broadband Map shows providers at a specific address.

City, state and U.S. shares · ACS 2020–2024
Measure	Mountlake Terrace	Washington	U.S.	Compared with Washington
People without health insurance Civilian noninstitutionalized population	7.1% ±1.8 pp	6.3%	8.4%	Not statistically different
Households with a broadband subscription Households	93.5% ±0.7 pp	93.6%	91.0%	Not statistically different
Veterans Civilian population age 18 and older	5.0% ±0.9 pp	7.8%	6.2%	Lower

Reading and reusing the estimates

The Census table links above lead to the original detailed tables. Counts, source universes and uncertainty are retained in the source observation download for Mountlake Terrace . Compare these figures with the same survey window; do not compare one city’s five-year estimate with another city’s annual estimate as though they measured the same period. For methods, see uncertainty and denominator calculations.

Read Mountlake Terrace housing and cost context or return to the city profile.