Table 1.

Description of Nine Rural-Urban Classifications

Name		Developer	Based on	Unit	Purpose	Classification	Database
1.	OMB (gold standard)	OMB	CBSA	County	Statistical purposes	3 Classes: MSA; MiSA; non-core:	N = 1,882 FIPS with CBSAs
2.	Urban-Rural Classification Scheme for Counties (URCSC)	(NCHS)	CBSA	County	Study the associations between urbanization level of residence and health and to monitor the health of urban and rural residents.	6 classes: 4-MSAs, 1-MiSA, 1-non-core	N= 3,149 FIPS
3.	Urban influence codes (UIC)	USDA	CBSA	County	Differences in economic opportunities among rural areas.	12 classes: 2 MSAs; 3 MiSA; 7 noncore	N= 3,221 FIPS
4.	Rural-urban continuum codes (RUCC)	USDA	CBSA	County	Degree of urbanization and adjacency to a metro area	9 classes: 3 MSA, 6 urban, 2 rural	N= 3,221 FIPS
5.	FORHP rural areas	FORHP	Multiple measures	County	Establish eligibility for funding opportunities	2 classes: rural, and non-rural.	2,590 rural FIPS; 18,776 rural ZIPs
6.	Index of relative rurality (IRR)	Purdue University	Multiple measures	County	Measure county’s degree of rurality	A scale from 0 to 1	N= 3,141 FIPS
7.	Percent of rural and urban	U.S. Census Bureau	Census measures	County	Statistical purposes	3 classes: mostly urban; mostly rural, and rural	N = 3,146 FIPS
8.	The Rural-Urban Commuting Area codes (RUCA)	USDA	CBSA	ZIP	Commuting patterns	10 classes: 3 urban, 3 large rural, 3 small rural; 1 isolated rural.	N = 74,002 FIPS (11 digit) N = 41,901 ZIPs
9.	Frontier and remote (FAR)	USDA	Multiple measures	ZIP	Access to goods and services	4 levels	30,337 remote ZIPs

Note. OMB = Office of Management and Budget; USDA = United States Department of Agriculture; NCHS = National Center for Health Statistics; FORHP = Federal Office of Rural Health Policy