List of Metropolitan Statistical Areas in the context of "National Capital Region (United States)"

The Washington metropolitan area, also referred to as the National Capital Region, Greater Washington, or locally as the DMV (short for District of Columbia, Maryland, and Virginia), is the metropolitan area comprising Washington, D.C., the federal capital of the United States, and its surroundings. The metropolitan area includes all of Washington, D.C., and parts of Maryland, Virginia and even West Virginia. The U.S. Government defines the area as the Washington–DC, VA–MD–WV metropolitan statistical area. It anchors the southern end of the densely populated Northeast megalopolis and is part of the Washington–Baltimore combined statistical area, the country's third-largest. The area's estimated total population of 6,304,975 (as of 2023) makes it the country's seventh-most populous metropolitan area. It is one of the country's most educated and affluent metropolitan areas.

The Phoenix metropolitan area, also known as the Valley of the Sun, the Salt River Valley, metro Phoenix, or The Valley, is the largest metropolitan statistical area in the Southwestern United States, with its largest principal city being the city of Phoenix. It includes much of central Arizona. The United States Office of Management and Budget designates the area as the Phoenix–Mesa–Chandler Metropolitan Statistical Area (MSA), defining it as Maricopa and Pinal counties. It anchors the Arizona Sun Corridor megaregion along with the second-most populous metropolitan area in the state, the Tucson metropolitan area. The gross domestic product of the Phoenix metropolitan area was around $400 billion in 2023, 14th highest amongst metro areas in the United States.

As of the 2020 census, the two-county metropolitan area had 4,845,832 residents, making it the 11th largest metropolitan area in the nation by population. Metro Phoenix grew by 652,945 people from April 2010 to April 2020, making it one of the fastest growing metro areas in the country. This also contributed to the entire state's exceptional growth; the area is home to just over two-thirds of Arizona's population. The population of the Phoenix metropolitan area increased by 45.3% from 1990 through 2000, compared to the overall U.S. rate of 13.2%, helping make Arizona the second-fastest growing state in the nation in the 1990s behind Nevada. The 2000 census reported the population of the metropolitan area to be 3,251,876. Water insecurity and drought in conjunction with climate change have become a significant concern for the metropolitan area's future growth prospects.

The Washington metropolitan area (also referred to as the National Capital Region, Greater Washington, or locally as the DMV, short for District of Columbia, Maryland, and Virginia) is the metropolitan area comprising Washington, D.C., the federal capital of the United States, and its surroundings. The metropolitan area includes all of Washington, D.C., and parts of Maryland, Virginia and even West Virginia.

The United States federal government defines the area as the Washington–DC, VA–MD–WV metropolitan statistical area. It anchors the southern end of the densely populated Northeast megalopolis and is part of the Washington–Baltimore combined statistical area, the country's third-largest. The area's estimated total population of 6,304,975 (as of 2023) makes it the country's seventh-most populous metropolitan area. It is one of the country's most educated and affluent metropolitan areas.

Montgomery County, colloquially referred to as Montco, is in the Commonwealth of Pennsylvania. As of the 2020 census, the population of the county was 856,553, making it the third-most populous county in Pennsylvania after Philadelphia and Allegheny counties and the most populous county in Pennsylvania without a major city.

The county seat and largest city is Norristown. The county is part of the Philadelphia–Camden–Wilmington PA-NJ–DE–MD metropolitan statistical area, known as the Delaware Valley, and marks the Delaware Valley's northern border with the Lehigh Valley region of eastern Pennsylvania.

Fairfield County is a county in the southwestern corner of the U.S. state of Connecticut. It is the most populous county in the state and was also its fastest-growing from 2010 to 2020. As of the 2020 census, the county's population was 957,419, representing 26.6% of Connecticut's overall population. The closest to the center of the New York metropolitan area, the county contains four of the state's seven largest cities—Bridgeport (first), Stamford (second), Norwalk (sixth) and Danbury (seventh)—whose combined population of 433,368 is nearly half the county's total population.

The United States Office of Management and Budget has designated Fairfield County as the Bridgeport–Stamford–Norwalk metropolitan statistical area. The United States Census Bureau ranked the metropolitan area as the 59th most populous metropolitan statistical area of the United States in 2019. The U.S. Office of Management and Budget has further designated the metropolitan statistical area as a component of the more extensive New York–Newark–Bridgeport, NY–NJ–CT–PA combined statistical area, the most populous combined statistical area and primary statistical area of the United States.

The Phoenix metropolitan area, also known as the Valley of the Sun, the Salt River Valley, metro Phoenix, or locally, The Valley, is the largest metropolitan statistical area in the Southwestern United States, with its largest principal city being the city of Phoenix. It includes much of central Arizona. The United States Office of Management and Budget designates the area as the Phoenix–Mesa–Chandler Metropolitan Statistical Area (MSA), defining it as Maricopa and Pinal counties. It anchors the Arizona Sun Corridor megaregion along with the second-most populous metropolitan area in the state, the Tucson metropolitan area. The gross domestic product of the Phoenix metropolitan area was around $400 billion in 2023, 14th highest amongst metro areas in the United States.

As of the 2020 census, the two-county metropolitan area had 4,845,832 residents, making it the 11th largest metropolitan area in the nation by population. Metro Phoenix grew by 652,945 people from April 2010 to April 2020, making it one of the fastest growing metro areas in the country. This also contributed to the entire state's exceptional growth; the area is home to just over two-thirds of Arizona's population. The population of the Phoenix metropolitan area increased by 45.3% from 1990 through 2000, compared to the overall U.S. rate of 13.2%, helping make Arizona the second-fastest growing state in the nation in the 1990s behind Nevada. The 2000 census reported the population of the metropolitan area to be 3,251,876. Water insecurity and drought in conjunction with climate change have become a significant concern for the metropolitan area's future growth prospects.