ZIP Code Tabulation Area · Maryland

ZIP Code 20659: St. Mary's County, MD

ZIP Code 20659 (St. Mary's County, Maryland) has an estimated 24,324 residents in 8,300 households. The median household income is $121,654, the median home value is $416,900 and the median gross rent is $1,527/mo. Figures are U.S. Census Bureau American Community Survey 2020–2024 5-year estimates for the matching ZIP Code Tabulation Area.

American Community Survey 2020–2024 5-year estimates · Updated

Total population

24,324

Margin of error ±1,447

Median household income

$121,654

Margin of error ±$10,429

Median home value

$416,900

Margin of error ±$15,967

Median gross rent

$1,527/mo

Margin of error ±$236

Median age

37.5 yrs

Margin of error ±1.7 yrs

Mean travel time to work

40.8 min

Margin of error ±5.5 min

How ZIP 20659 compares with Maryland and the U.S.

State and national figures are the Census Bureau's own estimates for those areas from the same ACS release, not averages of ZIP codes.

Median age

ZIP 2065937.5 yrsMaryland39.4 yrsUnited States38.9 yrs

Median household income

ZIP 20659$121,654Maryland$103,678United States$80,734

Per capita income

ZIP 20659$51,368Maryland$52,979United States$44,673

Poverty rate

ZIP 206597.5%Maryland9.4%United States12.5%

Unemployment rate

ZIP 206592.7%Maryland4.9%United States5.2%

Bachelor's degree or higher

ZIP 2065927.5%Maryland43.4%United States35.7%

Median home value

ZIP 20659$416,900Maryland$419,900United States$332,700

Median gross rent

ZIP 20659$1,527/moMaryland$1,705/moUnited States$1,413/mo

Owner-occupied homes

ZIP 2065988.6%Maryland67.6%United States65.2%

Mean travel time to work

ZIP 2065940.8 minMaryland31.1 minUnited States26.4 min

Worked from home

ZIP 2065914.5%Maryland19.3%United States15.1%

All figures for ZIP 20659

Each estimate has a 90% margin of error: the true value is likely within that range. * marks estimates with a large margin of error (a coefficient of variation above 30%, or ±10 percentage points or more for rates).

ZIP 20659 — ACS 2020–2024 5-year estimates
MeasureZIP 20659Margin of errorMarylandUnited States
Total population24,324±1,4476,206,011334,922,499
Median age37.5 yrs±1.7 yrs39.4 yrs38.9 yrs
Households8,300±4572,362,928129,227,496
Median household income$121,654±$10,429$103,678$80,734
Per capita income$51,368±$4,494$52,979$44,673
Poverty rate7.5%±2.3 pts9.4%12.5%
Unemployment rate2.7%±1.1 pts4.9%5.2%
Bachelor's degree or higher27.5%±3.3 pts43.4%35.7%
Median home value$416,900±$15,967$419,900$332,700
Median gross rent$1,527/mo±$236$1,705/mo$1,413/mo
Owner-occupied homes88.6%±3.6 pts67.6%65.2%
Mean travel time to work40.8 min±5.5 min31.1 min26.4 min
Worked from home14.5%±2.8 pts19.3%15.1%

Race and Hispanic or Latino origin

Shares of the total population by the Census Bureau's race and Hispanic or Latino origin categories (table B03002), listed in the Census Bureau's order. People self-identify on the survey.

Population by race and Hispanic or Latino origin, ZIP 20659
GroupZIP 20659MarylandUnited States
White alone, not Hispanic or Latino85.4%46.6%57.4%
Black or African American alone, not Hispanic or Latino5.3%28.9%11.9%
American Indian and Alaska Native alone, not Hispanic or Latino0.0%0.1%0.5%
Asian alone, not Hispanic or Latino1.1%6.5%5.9%
Native Hawaiian and Other Pacific Islander alone, not Hispanic or Latino0.0%0.0%0.2%
Some other race alone, not Hispanic or Latino0.3%0.7%0.6%
Two or more races, not Hispanic or Latino4.8%4.6%4.3%
Hispanic or Latino (of any race)3.1%12.5%19.3%

Where ZIP 20659 is

State
Maryland
Main county
St. Mary's County— also overlaps Charles County
Largest overlapping place
Mechanicsville (5% of the ZIP's land area)
Land area
97.01 sq mi· about 251 people per sq mi

County and place names come from the Census Bureau's 2020 ZCTA relationship files. A ZIP code's mailing city, set by the U.S. Postal Service, can differ from these names.

Other ZIP codes in St. Mary's County

20606 St. Mary's County, MD20609 St. Mary's County, MD20618 St. Mary's County, MD20619 California, MD20620 Callaway, MD20621 St. Mary's County, MD20624 St. Mary's County, MD20626 St. Mary's County, MD20628 St. Mary's County, MD20630 St. Mary's County, MD20634 California, MD20636 St. Mary's County, MD20650 St. Mary's County, MD20653 St. Mary's County, MD20656 St. Mary's County, MD20667 St. Mary's County, MD20670 St. Mary's County, MD20674 Piney Point, MD20680 St. Mary's County, MD20684 St. Mary's County, MD20686 St. Mary's County, MD20687 St. Mary's County, MD20690 Tall Timbers, MD20692 St. Mary's County, MD

See every ZIP code in Maryland, or compare ZIP 20659 with another ZIP code.

Census figures describe residents as a group and cannot tell you about any one home or street. For a specific address, check local government and housing records.

About ZIP codes and ZCTAs: the Census Bureau publishes statistics for ZIP Code Tabulation Areas, which approximate USPS ZIP code delivery areas. Learn how they differ.

Sources

  • U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, detailed tables B01003, B01002, B11001, B19013, B19301, B17001, B23025, B15003, B25077, B25064, B25003, B08013, B08303, B08301, B03002 — snapshot Oct 26, 2026.
  • U.S. Census Bureau, 2020 ZCTA5 relationship files (county and place).
  • Data: U.S. Census Bureau, American Community Survey 5-year estimates (detailed tables) and 2020 Census ZCTA relationship files. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. These agencies do not endorse OpenZIP.