Additional places that meet specific criteria are also identified as principal cities.
[1] The title of each metropolitan or micropolitan statistical area consists of the names of up to three of its principal cities and the name of each state into which the metropolitan or micropolitan statistical area extends.
[2] In the United States and Puerto Rico, the Office of Management and Budget identifies principal cities for each core-based statistical area (CBSA) and New England city and town area (NECTA).
Additional principal cities can be included if they satisfy certain criteria depending on their population.
Most recently on February 28, 2013, the Office of Management and Budget identified from one to 19 principal cities (in the Los Angeles metropolitan area) for each of the 929 CBSAs and 38 NECTAs of the United States and Puerto Rico.