United States admin level
Administrative boundaries delineate levels of government, displayed as differently-rendered boundary lines, among other uses (see re capital, heritage). The United States (US) Constitution's Tenth Amendment makes local government in the US a matter of state law, whereas the District of Columbia, territories and commonwealths are governed by federal law under the exclusive jurisdiction of the US Congress, distinct from states. As a result, the 50 states have a wide variety of administrative structures. Nearly all states have an administrative subdivision called "county" (or county equivalent, "municipality" serves this purpose in territories and commonwealths), while incorporated local municipalities in states include "city," "town" and "village." Beyond this prototypical structure (and broadly speaking), some regional generalizations emerge: found in most Midwestern states is a government between county and city called "township," while in New England, governments tend toward weak-county / strong-town, to where in one state (Rhode Island), "county" vanishes entirely. The US Department of Commerce's Census Bureau categorizes these administrative subdivisions every five years, with OSM usually aligning, though sometimes diverging: exceptions are noted due to slightly differing definitions and/or OSM consensus.
Instructions: in the US, tag a truly administrative / government (multi)polygon boundary with boundary=administrative and admin_level=* where the value of admin_level=* (4 through 10) is guided by this table (and wiki). Find the row with the state, district, territory or commonwealth in question (if not found, use "prototypical"), then find the administrative subdivision in question across that row. Use the number from the top of the resulting column as the value of admin_level=*. Quality assure (test/check) here.
|State, District, Territory or Commonwealth|
|District of Columbia||N/A||N/A||N/A||Washington||N/A||Neighborhood tagged as place=suburb|
|The prototypical state
for states not listed below:
|N/A||County||In states where these exist,
or any Minor civil division (MCD)
which is a government.
See Township (Civil township)
(in some states)
(in some states)
|In cities or towns where these exist,
|In cities or towns where these exist,
|In cities or towns where these exist,|
|New York||New York City||Borough||N/A||Community District||N/A|
|City of Sherrill||N/A|
|Rhode Island||N/A||Town||In towns where these exist,
|N/A||City||In cities where these exist,
(Boston has Districts and Wards)
|Vermont||N/A||County||N/A||Town||In towns where these exist,
incorporated Village 
Organized Gore, Grant, Purchase, Location
Planning Analysis Section (Philadelphia)
(colloquially called "town,"
but legally distinct),
might be entered as a node
|N/A||City (all are
|Ohio||N/A||County (details)||Township (details)||City
|Florida||N/A||County||Reedy Creek Improvement District||City
(synonymous by law)
|In cities or towns where these exist,
(sometimes unofficially called "Village"),
as defined by a city
|In cities or towns where these exist,|
+ name=* may be effective or preferred
|American Samoa||N/A||Municipality as District||County||Village||N/A|
as Unorganized Atoll
|Northern Mariana Islands||N/A||Municipality
|Puerto Rico||N/A||Municipio (Municipality)||N/A||Barrio (Ward) ||N/A||Sector or Sub-barrio (Section or Village) |
|United States Virgin Islands||N/A||Municipality as
|United States Minor Outlying Islands||N/A|
|State with Consolidated city-county
(the CCC's County)
|N/A||the CCC's City
(identical to its county)
|Specific instances of ICs in
|N/A||Independent Cities (ICs)
Native American reservations
There is no consensus yet on how to tag US American Indian Reservations. Different reservations have varying levels of interaction with local, state, and federal government agencies. These boundaries often cross state lines (in one case, a national border as well). These relationships are perhaps too complex to shoehorn into a hierarchical scheme like admin_level=*. Therefore, a common approach is to tag these with either boundary=aboriginal_lands or boundary=protected_area + protect_class=24, omitting the admin_level=* tag in either case. A complication are state recognized tribes in the US, as individual sovereign states recognize these tribes while the (federal) US Bureau of Indian Affairs does not. Also, specific distinctions should respect the unique entities of Hawaiian home land, Alaska Native tribal entities, Pueblo and Off-reservation trust land. Wikipedia states "tribal sovereignty is a form of parallel sovereignty within the U.S. constitutional framework, constrained by but not subordinate to other sovereign entities", where a map of the contiguous US (lower 48 states) with reservation lands excluded is displayed. In that light, admin_level=2 or no admin_level=* at all may be appropriate on each (sometimes called First Nations in Canada, to give a neighboring flavor to the semantics). Though several tagging solutions have been proposed, many have challenges: again, no firm consensus has emerged besides boundary=aboriginal_lands or boundary=protected_area + protect_class=24, omitting the admin_level=* tag.
Not all boundaries are administrative
Census Designated Places (CDPs) are boundaries maintained by the Census Bureau for statistical purposes. CDPs should be tagged boundary=census, ideally without an admin_level=* tag. In 2009, many CDPs were imported from TIGER as boundary=administrative + admin_level=8, but the talk-us mailing list reached a consensus to treat them as non-administrative boundaries. Additionally, the Census Bureau has revised its methodology regarding CDPs since 2009, causing many imported boundaries to fall out of date. There is some degree of support for removing the least relevant CDPs from OSM, but note that CDPs are relevant in some parts of the country, such as Alaska.
While boundary=census remains a useful tag in some circumstances, other Census Bureau definitions, such as "Metropolitan Statistical Area" (MSA) should not be entered into OSM as boundaries at all. According to the US Government (Departments of Labor and Commerce, Executive Office of the President's Office of Management and Budget), "the delineations are intended to provide a nationally consistent set of geographic areas for collecting, tabulating, and publishing federal statistics." Therefore, MSAs and similar entities (μSAs, CSAs, PSAs, CBSAs...) are not administrative boundaries. (See also Relations are not categories.)
So-called special districts, like Councils of Governments (COGs), Metropolitan Planning Organizations (MPOs) and California's Local Agency Formation Commissions (LAFCOs), were proposed in 2012 to be tagged boundary=administrative + admin_level=5. However, these proposals did not gain substantial consensus, so do not enter these with such tags. Also, boundary=school is found on school district boundaries, though it is quite rare: a recent taginfo shows boundary=administrative makes up about 89% of millions of OSM's boundary=* tags, yet there are fewer than ten boundary=school tags in all of OSM.
The Census Bureau offers a helpful-to-OSM recognition of five local government types in the US. Three are general-purpose governments: county (and "county equivalent"), township and municipal governments. The other two are special-purpose governments: special district governments and school district governments. OSM recognizes via consensus that the first three are tagged boundary=administrative + admin_level=6, 7, 8. The latter two are not tagged boundary=administrative, but rather are tagged as in the previous paragraph.
Consolidated city-counties, Independent cities
40 Consolidated city-counties (CCCs) are found across the US: in Alaska, California, Colorado, Florida, Georgia, Hawaii, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Montana, New Mexico, New York, North Carolina, Pennsylvania, Tennessee and Wisconsin. With the exception of New York City (NYC), all CCCs span a single county. It may seem redundant at first glance, however for single-county CCCs, "tag twice" two coterminous (multi)polygons tagged boundary=administrative: one with admin_level=6, another with admin_level=8 representing both county and city, respectively. Even with many subtle distinctions in how CCCs differ from one another, OSM tags these admin_level=6, while the agglomeration of NYC has emerged with wide US consensus as unique: NYC is the US's only "consolidated city-county of multiple counties" (or county equivalents), so we tag it admin_level=5. If other CCCs grow by agglomerating entire multiple counties, these new multiple-county CCCs can promote from admin_level=6 to admin_level=5 to be consistent with NYC (see Discussion). "Tag twice" such multiple-county CCCs: for NYC, admin_level=5 on the consolidated city and admin_level=6 on each borough (county or county equivalent).
An Independent city (IC) is "a city not in the territory of any county or counties." ICs differ from CCCs as there is only one (multi)polygon to tag (admin_level=6, not admin_level=8, nor both, as in the case of all but one of US's CCCs, NYC). ICs subordinate directly to their state (admin_level=4) with no intervening county, in what might be thought of as "a city with administrative level of (an urbanized) county, but not a county." In an example of consistency with the Census Bureau, OSM treats ICs as county equivalents.
Finally, an important distinction to note are the hundreds of US cities (admin_level=8) which extend in a minor way into more than a single county (admin_level=6), the city slightly egressing into two, three, four or even five counties (as does Dallas, Texas). These are not and differ from CCCs and ICs. They should be tagged the same as other "regular" cities (and counties), except that city boundaries happen to cross county boundaries beyond the city's "home" or "primary" county.
In US local government, an unincorporated area generally refers to the part of a county which is outside any incorporated municipality. Please see the Wikipedia article, as the topic is somewhat complex: most states have granted some form of "home rule," so that county commissions (or boards or councils) have the same powers in these areas as city councils or town councils have in their respective incorporated areas. Some states instead put these powers in the hands of "townships," minor civil divisions of each county, called "towns" in some states. Some states have no unincorporated land areas; these include Connecticut, Massachusetts, New Jersey, New York and Rhode Island, although these states all have communities that are not separately incorporated but are part of a larger municipality. Due to differences in state laws regarding the incorporation of communities, there is great variation in the distribution and nature of unincorporated areas.
It does not appear that OSM needs to (or can) explicitly delineate unincorporated areas on a closed (multi)polygon as boundary=administrative. For these communities, tag a node with name=* and place=*, as appropriate, omitting the admin_level=* tag in all cases (on a node). Some rough rules of thumb to have emerged in the US are:
- place=city only on incorporated cities (or legally towns, if population warrants it) especially when population exceeds 50,000,
- place=town on unincorporated communities with a population between 10,000 and 50,000,
- place=village on rural unincorporated communities with a population between 200 and 9,999,
- place=hamlet on rural unincorporated communities with a population between three households and 199 and
- place=isolated_dwelling on rural unincorporated communities with a population of not more than two households.
Federal enclaves, extraterritorial jurisdiction
A US federal enclave is a parcel of federal property within a state that is under the "Special Maritime and Territorial Jurisdiction of the United States." Last officially tabulated in 1960, there were about 5,000 such enclaves, with about one million people living on them. These numbers are undoubtedly lower today because many of these areas were military bases that have been closed and transferred out of federal ownership. However, many remain, especially in Alaska and Hawaii. Since the late 1950s, it has been official federal policy that the states should have "full concurrent jurisdiction" on all federal enclaves. Best tagging practices to achieve this goal of "both federal and state concurrent jurisdictions" are unknown, suggestions here are welcome.
The US federal government maintains exclusive jurisdiction over military installations and American embassies and consulates in foreign countries. Little to no OSM consensus has emerged regarding boundary=administrative tags on these entities.
The United States exercises some degree of extraterritorial jurisdiction in other areas. These include Guantánamo Bay Naval Base, a 45 mile2 (117 km2) area of land along Guantánamo Bay, Cuba as well as American scientific research stations in Antarctica: Amundsen–Scott South Pole Station, McMurdo Station and Palmer Station are under American jurisdiction, but held without sovereignty as per the Antarctic Treaty. Little to no OSM consensus has emerged regarding boundary=administrative tags on these entities.
Homeowner associations, CIDs, MTIPs
In the US, a homeowner association (HOA) is a private association formed by a real estate developer for the purpose of marketing, managing, and selling homes and lots in a residential subdivision. OSM has not reached a consensus on tagging HOAs in the US. It may be that consensus emerges to tag them boundary=administrative + admin_level=10 on a state-by-state basis, but that has not occurred. It may emerge that boundary=HOA is appropriate if it is determined (perhaps in a particular state with a particular body of HOA law, or lack thereof) that HOAs are not administrative boundaries. Ongoing legal discussions and emerging case law in many states continue to determine whether HOAs are de jure governments, even if they are de facto communities as a municipal corporation. It has begun to emerge, but is not universal, that landuse=residential + name=* tags appropriately capture these semantics without the need to additionally tag boundary=* with any particular value.
The fastest-growing form of housing in the US today are common-interest developments (CIDs), a category of housing that includes planned unit (or urban) developments (PUDs) of single-family homes, condominiums and cooperative apartments. An alternative to CIDs is the multiple-tenant income property (MTIP), known in the United Kingdom as "housing estates." CIDs and MTIPs have fundamentally different forms of governance from each other. As with HOAs, no OSM consensus has emerged for CIDs, PUDs or MTIPs with regard to boundary=* or admin_level=*.
- WikiProject United States/Boundaries, a less prescriptive, more descriptive, novice-friendly wiki to accompany this one.
- Admin level
- United States municipalities for a listing and reference information on US admin_level=8 entities.
-  describes which MCDs are governments starting on page 8-12.
- ITO Administrative Boundaries map
- OSM France map showing Admin Levels
- The District of Columbia may be considered an administrative subdivision of the United States at the same level as a territory or commonwealth. The District admin_level=4. is tagged with
- The city of Washington, coterminous with the District of Columbia, is considered by the Census Bureau as a "county equivalent," similar to a CCC, but strictly speaking, not a CCC. Washington is tagged with admin_level=8, not admin_level=6.
- The "prototypical" structure as it is expressed in this row is intended to reduce clutter in the table. States with explicit row entries intend to convey administrative structure which differ somewhat from this prototypical structure.
- There was a proposal in 2012 to map councils of governments (COGs) and metropolitan planning organizations (MPOs) as boundary=administrative + admin_level=5. It did not gain substantial consensus, so please do not tag these like this.
- The Census Bureau infers 20 states have townships: Connecticut, Illinois, Indiana, Kansas, Maine, Massachusetts, Michigan, Minnesota, Nebraska, New Hampshire, New Jersey, New York, North Dakota, Ohio, Pennsylvania, Rhode Island, South Dakota, Vermont and Wisconsin. Explicitly listing these 20 states with townships is intended to reduce clutter in the table. While admittedly confusing, it should be noted that while the Census Bureau infers a "civil" township in these states, some may be "nominal" townships only, that is, not a township in the sense of a direct county subdivision (admin_level=7), but rather only named "township," and actually a small city (as in New Hampshire, New Jersey and Pennsylvania), so admin_level=8 is more appropriate there.
- While it does not occur frequently over the whole of 3000+ United States counties, there are hundreds of city boundaries which extend beyond a single county in a minor way, the city slightly egressing into two, three or even four or five counties. In some states (Alabama, Minnesota, Ohio, Texas) this happens dozens of times, and so might be "somewhat frequent." These are not and differ from CCCs and ICs. New York City, a unique case, fully encompasses five county equivalents, different than these "egressing cities."
- Louisiana is divided into 64 parishes in the same way that 47 of the other 50 states of the United States are divided into counties. A Louisiana parish is sometimes called a county equivalent.
- Unlike counties or county equivalents in the other 49 states, Alaska's 19 organized boroughs do not cover the entire land area of the state, leaving a large area (larger than any other state) known as the Unorganized Borough. An Alaska (organized) borough is sometimes called a county equivalent, although in the case of the Unorganized Borough this is not strictly accurate, as the Unorganized Borough is administered solely by the state to a large degree. (As an example of an exception to state administration in the Unorganized Borough, minor school district administration may happen locally). The Census Bureau, in cooperation with the state of Alaska, further divides the Unorganized Borough into ten census areas. Boroughs and census areas within the Unorganized Borough are both treated as county equivalents by the Census Bureau, however, in a divergence from the Census Bureau, OSM does not treat census-defined areas within the Unorganized Borough as county equivalents, so tag these boundary=census.
- Anchorage, Haines, Juneau, Sitka, Wrangell and Yakutat classify as consolidated city-boroughs (same as CCCs, two coterminous areas, one tagged admin_level=6, the other tagged admin_level=8), rather than cities (admin_level=8 alone). These all include City and Borough in their names, except for Anchorage, officially named Municipality of Anchorage, considered a consolidated city-borough under state law.
- In New York, a "Town" is effectively equivalent to an "incorporated township" in other states. In New York, it is also possible for a Town to be coterminous with its single Village in an entity known as a consolidated city-township.
- In New York, a village may be coterminous with its town. Wikipedia says: "Such a local government is called a coterminous town-village and is governed under Article 17 of the New York Village Law. It is never called a consolidated city-township because New York's cities, as opposed to its villages, exist outside of town areas. Five towns are coterminous with their single village: Green Island in Albany County; East Rochester in Monroe County; and Scarsdale, Harrison and Mount Kisco in Westchester County."
- Connecticut's court jurisdictions still adhere to the county boundaries, except for Fairfield, Hartford and New Haven, which have been further subdivided into several jurisdictions.
- In 1960 Connecticut dissolved its county governments creating a vacuum of power at the regional level. In the 1980s the state established 15 regional councils with authority limited to land use policymaking, infrastructure development, emergency preparedness, and long-term planning. Effectively, counties are geographic entities, but not governmental jurisdictions, except for courts, while regions have limited authority, meaning most government administration is at state (4) and local (8, 9) levels. Eight of the nine regions contain "Council of Governments" in their name, the exception is the Greater Bridgeport Regional Council. Even though "Region" is entered into the table, per this consensus, these should not be tagged with boundary=administrative. (This note had to be anchored somewhere!) See Local government in Connecticut.
- Towns in New England are municipal corporations, with their powers defined by a combination of municipal corporate charter, state statutes, and the state constitution.
- At one time, all New England cities were non-coextensive with their underlying town; the practice of making cities coextensive with their towns was a later adaptation intended to mimic the city concept that had emerged in the other New England states. Over time, many non-coextensive cities have expanded to become coextensive with their parent town. As with boroughs, many have also disincorporated and reverted to full town control. Wikipedia states: (as) "the entire area of Connecticut is divided into towns, cities and boroughs are within town areas and their governments may or may not be consolidated with those of the towns in which they are located."
- There are no legal restrictions in Connecticut that would prevent a city or borough today from overlaying the territory of more than one town, provided it is not consolidated with one of the underlying towns. In New England, non-coextensive cities have become very rare.
- While it is geographically divided into five counties, Rhode Island effectively has no government at the county level. This is similar to Connecticut, but even more strict, as not even court jurisdictions are defined at the county level. This means all government administration is at state (4) and local (8, 9) levels.
- Geographically divided into 14 counties, Massachusetts effectively has no county government in eight of them, similar to Rhode Island. This means in these eight counties (Berkshire, Essex, Franklin, Hampden, Hampshire, Middlesex, Suffolk and Worcester), all government administration is at state (4) and local (8, 9) levels. However, several functions implemented by the state are organized by county lines, including District Attorney, Sheriff and the judiciary.
- Unincorporated territory in New England states, only found in Maine and in small areas of New Hampshire and Vermont is unorganized and not part of any town, city or plantation. There are also "leftover" areas not included in any town in these three states known by a variety of names, including gores, grants, locations, purchases, surpluses and strips. New Hampshire's Coös County contains six unorganized townships that do not appear to have ever been actively incorporated, Vermont's Essex County contains three of these, and Maine has hundreds of them. These three states also include at least one unorganized township that was once a town, but has disincorporated and reverted to unorganized territory (in Maine these were once organized as plantations). Both City and Town are incorporated and organized, and in Maine, Plantations are organized but unincorporated and unorganized unincorporated territory is known as a Township.
- Vermont has 37 incorporated villages (history). Other villages and hamlets do not have separate government apart from their Town and have indistinct borders mostly defined by the expansion of water/sewer/sidewalk and similar services. These unincorporated areas should be mapped as a node without an admin_level=* tag.
- In Vermont, if a village becomes a city, it does not continue to overlay (be coterminous with) its parent town, but breaks away and becomes a completely separate municipality.
- Gores are unincorporated areas generally left over from 18th-century survey inaccuracies or areas never annexed by a Town or too small to form a Town. They tend to be mountain ridges-tops and other less-desirable land and so have very low populations, insufficient to support a local government. They are administered by the State in lieu of a functioning local government.
- Similar to the rest of New England, county government in New Hampshire is very weak and has relatively few responsibilities compared to states in other regions: usually only for the judiciary districts, local sheriff, jail services and nursing homes. Most local government functions are performed at the town and city (8) levels.
- Hamlets and villages are not noted here, as they are informal, unincorporated divisions of a township. Where they officially exist at all, they are simply Census Designated Places tagged with boundary=census, and thus don't fit into this table at all.
- New Jersey is unique in the United States for having five distinct types of incorporated municipalities. Each type of municipality has equal legal standing, rights, and powers as any other type or form. Unlike other parts of the United States, New Jersey does not have different tiers of power or legal standing for its municipal governments. Each of the five types has an associated form of government of exactly the same title. By default municipalities have the form of government which corresponds to their type, i.e. a Township has the Township form of government. In New Jersey a municipality can choose a different form of government if its citizens do not wish to operate under the form that matches its type.
- Since 1871, all incorporated cities in Virginia have classified as independent cities (ICs). Of the 42 ICs in the US, 39 are in Virginia, whose state constitution makes them a special case. In Virginia when multiple local governments consolidate to form a city (legally an IC), it may be divided into geographical subdivisions called "boroughs", which may be the same as the existing cities, counties, or portions of such counties. To emphasize: these boroughs are not separate local governments, they are geographical in nature.
- In Michigan, the state universities are constitutionally autonomous jurisdictions, possessed of a special status somewhat equivalent to that of metropolitan municipality. That is, as bodies corporate, they operate as though they were municipalities, but they have autonomy from legislative and executive control. Each university has a board which is the sole legislative body for the campuses they control. These campuses are independent of all state laws, and under the sole control of the boards. The boards are responsible for all public services, e.g. policing, and fire protection. They often contract with the city they are located in for these services, but all have their own police departments.
- In Michigan, townships (including charter townships) and cities are mutually exclusive administrative subdivisions under the county level. No part of a township lies within a city and if the entire township is incorporated as a city or annexed to a city, the township ceases to exist in every sense.
- In Michigan, a city can be part of more than one county. County boundaries are not adjusted according to city boundaries. There are no independent cities or consolidated city-counties.
- In Michigan, a charter township is equal to any other township, it is not an incorporated municipality. The charter in its name refers to the exercise of local options for township government provided by state law, an aspect of "home rule."
- In Michigan, a village is subordinate to a township and can span more than one township. Villages can also span more than one county.
- Portions of some Minnesota counties are "unorganized" — that is, not a township or city — and are governed by the county board. As such, they have no boundary=administrative of their own, but will display as "holes" in other such boundaries.
- Minnesota's townships were formed from the Congressional townships formed by the Public Land Survey, but have often been modified since then. However, they always remain in one county. In Minnesota, townships and cities are mutually exclusive administrative subdivisions under the county level. No part of a township lies within a city and if the entire township is incorporated as a city or annexed to a city, the township ceases to exist in every sense. Cities may sometimes detach land back to surrounding townships, or even be entirely dissolved and become part of a township. NOTE: Township boundaries in Minnesota are not currently entered in OSM.
- In Minnesota, as in many other states, a city can be part of more than one county. County boundaries are not adjusted according to city boundaries. In this sense, Minnesota's structure in the table is likely prototypical for several other (often northeastern or midwestern) states.
- Some cities such as Minneapolis have well-defined neighborhood boundaries that are used by neighborhood organizations.
- For neighborhood councils in Ohio's largest cities. May or may not correspond to voting wards. Use discretion; smaller cities' neighborhoods may be better served by landuse polygons.
- In Wisconsin, what is called a Town is effectively equivalent to Township in the rest of the US. In this sense, Wisconsin's structure in the table is likely prototypical for several other (often northeastern or midwestern) states.
- Wikipedia states: "The Illinois Township Code includes provisions for a municipality coextensive with a township. Such a municipality is known variously as a coterminous city and a coterminous municipality and the township is called a coterminous township. None are known here or entered in OSM.
- See this, which says that of the 102 counties in Illinois, 17 (west central, southern) of them are divided into 261 precincts and the remaining 85 counties are divided into 1433 townships.
- There was a proposal in 2012 to map California's Local Agency Formation Commissions (LAFCOs) as boundary=administrative + admin_level=5. It did not gain substantial consensus, so please do not tag these like this.
- California pioneered (in Lakewood) the concept of a "contract city" whereby a city contracts one or more municipal services to another unit of government, or to a private or commercial organization, often via a "franchise" agreement. Most of the contracts are for police or fire / rescue / paramedic services to the county in which the city lies or a neighboring city. Contract cities also exist in other states, such as Colorado and Georgia.
- Unique to Hawaii is the lack of municipal governments. All local governments are generally administered at the county level. The only incorporated area in the state is Honolulu County, a consolidated city–county that governs the entire island of Oahu. Entities resembling local government are in fact special-purpose districts. This means all government administration is at state (4) and county (6) levels.
- American Samoa, a substantially populated unincorporated unorganized territory, is divided into five municipalities: three districts (Eastern, Western, Manu'a) and two unorganized atolls (Rose Atoll, Swains Island). In Territories and Commonwealths, "Municipality" has a distinct meaning as county equivalent (admin_level=6), rather than the sense of "municipality" in the 50 states meaning a city, town or village (admin_level=8). This is true even in American Samoa, as the admin_level=* immediately below Municipality (admin_level=6) in Districts is, in fact, County (admin_level=7), which can have a subordinate level of Village (admin_level=8). Unorganized atolls have no admin_level=* below admin_level=6.
- The Commonwealth of Northern Mariana Islands is divided into four municipalities: Islands north of Saipan form the Northern Islands Municipality, although because of volcanic threat, these were evacuated and remain uninhabited. The three main islands of the Southern Islands form the municipalities of Saipan, Tinian, and Rota, with uninhabited Aguijan forming part of Tinian municipality.
- Consistent with OSM's characterization of Municipio as admin_level=6, the Census Bureau defines a Municipio as a county equivalent, similar to parish in Louisiana or borough in Alaska. Every municipality has at least one barrio called Pueblo which is home to the largest urban area of the municipality, and the political seat of the municipality. Most municipalities have a single barrio named Pueblo while others, most prominently the larger municipalities, may have a barrio Pueblo that is made of several barrios.
- An urban core with a population of 50,000 or above is considered a ciudad (city), while one with under 50,000 inhabitants is termed pueblo (town).
- The US Census Bureau further breaks down some barrios in Puerto Rico into sub-barrios. It is unclear whether this is best represented as sub-barrio, sector or village. See Barrios of Puerto Rico.
- There are exactly two territorial municipalities as "districts" in the U.S. Virgin Islands: the St. Croix district and the St. Thomas-St. John district. These are well-mapped in OSM, though the two islands are not properly combined as a single district. The subdistricts (nine, seven and four on those islands, respectively) are not well-mapped.
- There are no further administrative subdivisions below the admin_level=2 tag applied to the territorial waters surrounding these islands. As USMOI is technically a statistical grouping (each island or island group is actually an individual territory directly administered by a US federal government unit) this grouping should not have an admin_level=4 tag. Let's keep the relation as a convenient grouping.
All but three of USMOI are uninhabited. In the Pacific Ocean, Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Wake Island's wildlife and most of Palmyra Atoll are administered by US Department of Interior, Fish and Wildlife Service (land areas) and US Department of Commerce, National Oceanic and Atmospheric Administration (ocean areas) as Pacific Remote Islands Marine National Monument. Parts of Palmyra Atoll (Cooper Island and ten other land parcels) are privately administered by The Nature Conservancy, Inc. which manages them as a nature reserve. Palmyra Atoll is the US' only incorporated unorganized territory, with a population between 4 and 20. All other USMOI are unincorporated unorganized territories.
Midway Islands are also under US Fish and Wildlife Service jurisdiction as Midway Atoll National Wildlife Refuge and Battle of Midway National Memorial, part of the greater Northwestern Hawaiian Islands Marine National Monument (Papahānaumokuākea, which also includes Hawaiian Islands National Wildlife Refuge). About 50 people live on Midway's Sand Island, all are US Fish and Wildlife Service staff or contract workers.
Wake Island is a restricted-access active airfield administered by the US Department of Defense (Air Force) under a US Department of Interior agreement, population about 94. Wake Island is also claimed (as Enen-kio) by the Republic of the Marshall Islands.
In the Caribbean Sea, Navassa Island, Serranilla Bank and Bajo Nuevo Bank are also uninhabited unincorporated unorganized territories of the US, though disputed: the first claimed by Haiti, the latter two administered by Colombia, though claimed by the US (since 1879 under the Guano Islands Act) as well as by Jamaica and Nicaragua. Serranilla Bank is also claimed by Honduras. In 2012, a claim for Serranilla Bank and Bajo Nuevo Bank was resolved in favor of Colombia by the UN International Court of Justice.
- As of 2017, there are 40 consolidated city-counties in the US, including Anchorage, Butte, Denver, Honolulu, Indianapolis, Jacksonville, Kansas City, Lexington, Louisville, Nantucket, New Orleans, Philadelphia and San Francisco. For example, San Francisco is both a county (political division) of California, and an incorporated city, which includes seemingly redundant administration in some cases: it has both County Sheriff deputies as well as City Police officers, each of which serve distinct legal purposes (and act with mutual aid when necessary).
- Established by the Constitution of Maryland, Baltimore is not part of any county and is the largest independent city in the United States. A separate entity, Baltimore city is distinct from Baltimore County, not consolidated with it.
- In an act of "urban secession," Saint Louis separated from Saint Louis County in 1877, becoming an independent city and limiting its own political boundaries. A separate entity, Saint Louis city is distinct from Saint Louis County, not consolidated with it.
- The Consolidated Municipality of Carson City is an independent city, meaning it has effectively subsumed Ormsby County, which no longer exists. While "Consolidated" remains in the official name of Carson City, it is an independent city, not a consolidated city-county; there is no longer an Ormsby County.
- See WikiProject US_American_Indian_Reservations, WikiProject United States/Boundaries and threads beginning at:    
- See threads beginning at: