If you were planning on visiting that great urban cluster of Charlestown, New Hampshire, any time soon – sorry, you’re too late. It’s now rural.

Same with Epping and Farmington. Until this year those three communities rubbed shoulders with Concord, Keene and the Lebanon-Hanover megalopolis in the club of New Hampshire urban areas, but they’ve been pushed out.

It’s not that they have shrunk, with vibrant downtowns turned into cow pastures. If anything, their populations may have grown slightly as part of the pandemic’s flight from big cities.

The difference is that the Census Bureau has changed a decades-old classification system.

Until last month, the Census Bureau said New Hampshire had four “urbanized areas” – Manchester, Nashua, Portsmouth and Dover-Rochester – and 17 “urban clusters,” including Concord.

These definitions had nothing to do with local definitions (New Hampshire has 13 cities as defined by the form of government). They also ignore some obvious borders: Nashua’s area includes a little bit of Massachusetts and Portsmouth has a little bit of Maine, while a few places were mushed together such as Dover-Rochester and Lebanon-Hanover.

The definitions are part of long-running attempts to classify regions based on population density and connectedness, to better understand their needs and how they’re likely to change over time. But now, after much debate, the Census Bureau has now altered the definitions.

Under the old criteria, an urbanized area needed to have at least 50,000 residents (Concord just missed it) and an urban cluster had at least 2,500 people, a threshold that had been around since 1910.

Under the new definition, hammered out after the 2020 census, the minimum population required for an area to be considered urban doubled to 5,000 people – that’s what kicked out Charlestown, Epping and Farmington – and the distinction between an urbanized area and an urban cluster was eliminated.

The Census Bureau also added housing units to the definition of an urban area. A place can be considered urban if it has at least 2,000 housing units, based on the calculation that the average household has 2.5 people.

Now New Hampshire has 18 “urban areas,” some as big as Manchester and some as small as Littleton or Jaffrey. Concord and Franklin are among them but not Bow, Loudon or Warner.

Surprisingly, neither Derry nor Merrimack are considered “urban areas” despite the fact they have far more people than Franklin. Presumably that’s because they are more spread out, without a single cluster of relatively dense housing as in Conway or Jaffrey, smaller communities that are “urban areas.”

Why do we care about this bureaucratic hair-splitting? Money, of course.

Rural and urban areas often qualify for different types of federal funding for transportation, housing, health care, education and agriculture. The federal government doesn’t have a standard definition of urban or rural, so the Census Bureau’s definition is often used.

The bureau adjusts the definition after every once-a-decade census. The bureau says it is done for statistical purposes and it has no control over how government agencies use the definitions to distribute funding. There were 2,646 urban areas in the mainland U.S., Puerto Rico and U.S. islands on the list, released in late December.

It’s not clear what, if anything, the change will do to federal-funding chances for our three formerly urban locales. But if you’re a census fan looking for that big-city feel, you can cross Epping off your bucket list.