CPI area aggregation

All Consumer Price Index (CPI) series are constructed from one or more basic indexes. A basic index is the index for one of 243 basic items [1] in one of the 32 basic areas, for example apples (SEFK01) in the New York-Newark-Jersey City, NY-NJ-PA CBSA (S12A). Taking each unique combination of such items and areas results in 7,776 (243 x 32) item-area combinations that form the basic building blocks of CPI series.

The 32 basic areas in the CPI are composed of the 75 primary sampling units (PSUs) from which the survey data used to construct the CPI is collected. These 32 basic areas can be divided into two groups, 23 self-representing and 9 non-self-representing. Metropolitan areas with a population greater than 2.5 million people as of the 2010 Census are classed as ‘self-representing’ and included automatically in this group. Anchorage, AK and Honolulu, HI are also automatically selected despite not meeting this population threshold due to their unique geographic characteristics. The remaining PSUs are selected to represent other similar PSUs in the United States, and are termed ‘non-self-representing’, these non-self-representing PSUs are grouped into one non-self-representing area for each Census division. You can read more about the geographic area design of the CPI in Consumer Price Index Geographic Revision for 2018.

CPI areas can be divided into several categories:

Primary sampling units (PSUs) are sampled areas in which data are collected for the price surveys which provide much of the data used in the CPI. Each of the basic areas used to construct the CPI is composed of one or more PSUs. Each PSU, in turn, is composed of one or more core-based statistical areas (CBSAs) as defined by the Office of Management and Budget (OMB) [2]. The definitions of each PSU can be found in CPI Handbook of Methods Appendix 1: CPI Geographic Sample, 2018. Selected CPI series are published for the 23 self-representing PSUs.
Size classes are two aggregate areas which divide the CPI geography into self-representing and non-self-representing parts. The self-representing areas are grouped into size class A (S000), while the non-self-representing areas are grouped into size class B/C (N000). Selected CPI series are published for the size classes.
Census regions are groupings of states that subdivide the United States into four parts: the Northeast (0100), Midwest (0200), South (0300), and West (0400) regions. A map showing the four Census regions is available on the CPI regional resources page. All basic areas located within the states assigned to a Census region are components of the aggregate area for that Census region. Selected CPI series are published for the Census regions.
Census divisions are groupings of states that subdivide each Census region into two or more parts. For example, the Northeast (0100) Census region is divided into the New England (0110) and Middle Atlantic (0120) Census divisions. A map and table showing which states are assigned to each Census division is available from the Census Bureau [3]. All basic areas located within the states assigned to a Census division are components of the aggregate area for that Census division. Selected CPI series are published for the Census divisions.
Regional size classes represent the intersection of the four Census regions and the two size classes. Each Census region is divided into its self-representing (size class A) and non-self-representing (size class B/C) parts. So, for example, the Midwest (0200) Census region is split into the Midwest – size class A (S200) and Midwest – size class B/C (N200) regional size classes. Selected CPI series are published for the regional size classes.
The U.S. city average (0000) is the top-level series which combines all basic areas. (Or, alternatively, the U.S. city average combines all series of any level which is complete and mutually exclusive in its coverage of basic areas, like Census regions or Census divisions.)

Details on which CPI series are published in each area are available in CPI Handbook of Methods Appendix 7: CPI Items by Publication Level. A list of CPI area codes used in our databases is also available.

Table 1. Aggregate areas for which CPI data are published
Area code	Area title	Area type	Included areas
0000	U.S. city average	US	N110, N120, N230, N240, N350, N360, N370, N480, N499, S11A, S12A, S12B, S23A, S23B, S24A, S24B, S35A, S35B, S35C, S35D, S35E, S37A, S37B, S48A, S48B, S49A, S49B, S49C, S49D, S49E, S49F, S49G
0100	Northeast	Census region	N110, N120, S11A, S12A, S12B
0110	New England	Cenus division	N110, S11A
0120	Middle Atlantic	Cenus division	N120, S12A, S12B
0200	Midwest	Census region	N230, N240, S23A, S23B, S24A, S24B
0230	East North Central	Cenus division	N230, S23A, S23B
0240	West North Central	Cenus division	N240, S24A, S24B
0300	South	Census region	N350, N360, N370, S35A, S35B, S35C, S35D, S35E, S37A, S37B
0350	South Atlantic	Cenus division	N350, S35A, S35B, S35C, S35D, S35E
0360	East South Central	Cenus division	N360
0370	West South Central	Cenus division	N370, S37A, S37B
0400	West	Census region	N480, N499, S48A, S48B, S49A, S49B, S49C, S49D, S49E, S49F, S49G
0480	Mountain	Cenus division	N480, S48A, S48B
0490	Pacific	Cenus division	N499, S49A, S49B, S49C, S49D, S49E, S49F, S49G
N000	Size Class B/C	Size class	N110, N120, N230, N240, N350, N360, N370, N480, N499, S49F, S49G
N100	Northeast - Size Class B/C	Regional size class	N110, N120
N200	Midwest - Size Class B/C	Regional size class	N230, N240
N300	South - Size Class B/C	Regional size class	N350, N360, N370
N400	West - Size Class B/C	Regional size class	N480, N499, S49F, S49G
S000	Size Class A	Size class	S11A, S12A, S12B, S23A, S23B, S24A, S24B, S35A, S35B, S35C, S35D, S35E, S37A, S37B, S48A, S48B, S49A, S49B, S49C, S49D, S49E
S100	Northeast - Size Class A	Regional size class	S11A, S12A, S12B
S200	Midwest - Size Class A	Regional size class	S23A, S23B, S24A, S24B
S300	South - Size Class A	Regional size class	S35A, S35B, S35C, S35D, S35E, S37A, S37B
S400	West - Size Class A	Regional size class	S48A, S48B, S49A, S49B, S49C, S49D, S49E

Table 2. Contents of non-self-representing census division basic areas
Area code	Area title	Included PSUs	PSU Names
N110	New England non-self-representing	N11B, N11C	N11B: Hartford–West Hartford–East Hartford, CT; N11C: Springfield, MA
N120	Middle Atlantic non-self-representing	N12C, N12D, N12E, N12F	N12C: Pittsburgh, PA; N12D: Buffalo–Cheektowaga–Niagara Falls, NY; N12E: Rochester, NY; N12F: Reading, PA
N230	East North Central non-self-representing	N23C, N23D, N23E, N23F, N23G, N23H, N23I, N23J	N23C: Cincinnati, OH–KY–IN; N23D: Cleveland–Elyria, OH; N23E: Columbus, OH; N23F: Milwaukee–Waukesha–West Allis, WI; N23G: Dayton, OH; N23H: Flint, MI; N23I: Janesville–Beloit, WI; N23J: Frankfort, IN
N240	West North Central non-self-representing	N24C, N24D, N24E, N24F	N24C: Omaha–Council Bluffs, NE–IA; N24D: Wichita, KS; N24E: Lincoln, NE; N24F: Brookings, SD
N350	South Atlantic non-self-representing	N35F, N35G, N35H, N35I, N35J, N35K, N35L, N35M, N35N, N35O, N35P, N35Q	N35F: Charlotte–Concord–Gastonia, NC–SC; N35G: Orlando–Kissimmee–Sanford, FL; N35H: Richmond, VA; N35I: Raleigh, NC; N35J: Greenville–Anderson–Mauldin, SC; N35K: Winston–Salem, NC; N35L: Cape Coral–Fort Myers, FL; N35M: Ocala, FL; N35N: Gainesville, FL; N35O: Wilmington, NC; N35P: Jacksonville, NC; N35Q: Clarksburg, WV
N360	East South Central non-self-representing	N36A, N36B, N36C, N36D, N36E, N36F	N36A: Louisville/Jefferson County, KY–IN; N36B: Birmingham–Hoover, AL; N36C: Chattanooga, TN–GA; N36D: Huntsville, AL; N36E: Florence–Muscle Shoals, AL; N36F: Meridian, MS
N370	West South Central non-self-representing	N37C, N37D, N37E, N37F, N37G, N37H, N37I, N37J	N37C: San Antonio–New Braunfels, TX; N37D: Oklahoma City, OK; N37E: Baton Rouge, LA; N37F: Lafayette, LA; N37G: Brownsville–Harlingen, TX; N37H: Amarillo, TX; N37I: Russellville, AR; N37J: Paris, TX
N480	Mountain non-self-representing	N48C, N48D, N48E, N48F	N48C: Las Vegas–Henderson–Paradise, NV; N48D: Provo–Orem, UT; N48E: Yuma, AZ; N48F: St. George, UT
N499	Pacific non-self-representing other than Urban Hawaii and Urban Alaska	N49H, N49I, N49J, N49K	N49H: Portland–Vancouver–Hillsboro, OR–WA; N49I: Santa Rosa, CA; N49J: Chico, CA; N49K: Moses Lake, WA

Download an XLSX version of these tables here:

Table 1: Aggregate areas for which CPI data are published and Table 2: Contents of non-self-representing Census division basic areas (XLSX)

Footnotes:

[1] You can read more about the CPI item structure on the CPI item aggregation page, and you can see the item definitions in CPI Handbook of Methods Appendix 2: Content of CPI Entry Level Items.

[2]Core-based statistical areas (CBSAs) consist of the county or counties or equivalent entities associated with at least one core (urbanized area or urban cluster) of at least 10,000 population, plus adjacent counties having a high degree of social and economic integration with the core as measured through commuting ties with the counties associated with the core. Additional information can be found in Revised delineations of metropolitan statistical areas, micropolitan statistical areas, and combined statistical areas, and guidance on uses of the delineations of these areas, Bulletin No. 13-01 (Office of Management and Budget, February 28, 2013).

[3]Census Regions and Divisions of the United States, U.S. Census Bureau.

Last modified date: September 28, 2026