Maine statistical areas

The U.S. State of Maine currently has five statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated one combined statistical area, three metropolitan statistical areas, and one micropolitan statistical area in Maine.^[1] As of 2023, the largest of these is the Portland-Lewiston-South Portland, ME CSA, comprising the region around Maine's largest city of Portland.

Background

The Office of Management and Budget (OMB) has designated more than 1,000 statistical areas for the United States and Puerto Rico.^[2] These statistical areas are important geographic delineations of population clusters used by the OMB, the United States Census Bureau, planning organizations, and federal, state, and local government entities.

The OMB defines a core-based statistical area (commonly referred to as a CBSA) as the county or counties (or county-equivalents) surrounding at least one densely-settled core of at least 10,000 population,^[2] "plus adjacent counties having a high degree of social and economic integration with the core as measured through commuting ties with the counties containing the core".^[2] The OMB further divides core-based statistical areas based on population into metropolitan statistical areas (MSAs) for those with at least 50,000 and micropolitan statistical areas (μSAs) for those with 10,000 to 49,999 people.^[2]

The OMB defines a combined statistical area (CSA) as two or more adjacent core-based statistical areas where the employment interchange rate (% commuting from A to B plus % commuting from B to A) is at least 15%.^[2] The primary statistical areas (PSAs) include all combined statistical areas and any core-based statistical area that is not a constituent of a combined statistical area.

Table

The five United States statistical areas and 16 counties of the State of Maine
Core-based statistical area^[1]	2023 population (est.)^[3]	County	2023 population (est.)^[3]
Portland-Lewiston-South Portland, ME CSA	680,094	Portland-South Portland, ME MSA	566,329	Cumberland County, Maine	310,230
				York County, Maine	218,586
				Sagadahoc County, Maine	37,513
		Lewiston-Auburn, ME MSA	113,765	Androscoggin County, Maine	113,765
none		Bangor, ME MSA	155,312	Penobscot County, Maine	155,312
		Augusta-Waterville, ME μSA	127,259	Kennebec County, Maine	127,259
		none		Aroostook County, Maine	67,351
				Oxford County, Maine	59,905
				Hancock County, Maine	56,526
				Somerset County, Maine	51,302
				Knox County, Maine	40,977
				Waldo County, Maine	40,620
				Lincoln County, Maine	36,507
				Washington County, Maine	31,555
				Franklin County, Maine	30,828
				Piscataquis County, Maine	17,486
State of Maine					1,395,722

Primary statistical areas

Primary statistical areas (PSAs) include all combined statistical areas and any core-based statistical area that is not a constituent of a combined statistical area. Of the five statistical areas of Maine, three are PSAs comprising one combined statistical area, one metropolitan statistical area and one micropolitan statistical area.

The three primary statistical areas of the State of Maine
2020 rank	Primary statistical area^[1]	Population
2020 rank	Primary statistical area^[1]	2023 estimate^[3]	Change	2020 Census^[4]	Change	2010 Census^[5]
1	Portland-Lewiston-South Portland, ME CSA	680,094	+2.60%	662,879	+6.61%	621,800
2	Bangor, ME MSA	155,312	+2.05%	152,199	−1.12%	153,923
3	Augusta-Waterville, ME μSA	127,259	+2.93%	123,642	+1.22%	122,151