Census tracts with 4, 5, 6 and 10 tier classifications.  We'll be adding 2020 data when its available from the USDA or the Census.From Asnake Hailu,The schemes shared in the RUCAGuide.pdf are DOH modified layers, prepared merely for epidemiological purposes [I.e., to delineate geography for a comprehensive epidemiologic assessment, describing rural-urban differences in demographics, health outcomes, risk factors, access to services, and the like.] Those are not as such rural/urban designation tools for census block areas, nor for any of the other geography categories. The files with the DOH modified layers are available at https://doh.wa.gov/public-health-healthcare-providers/rural-health/data-maps-and-other-resources under the sub-county level: Zip Code and Census Tract sub-heading.Please note: those files are essentially a decade old. We were anticipating to update our core products that are on our website, if and when the Federal Office of Rural Health and Policy (FORHP) produces a newer version of RUCA codes based on census 2020. The FORHP customarily contracts with a university for that task. We are three years away from 2020, except there is no update posted on the webpage I am familiar to get the original RUCA delineations. Here is a path where I go to check for the newer version: https://www.ers.usda.gov/data-products/rural-urban-commuting-area-codes/