The goal of this paper is to release a methodology to produce county-level Supplemental Poverty Measure (SPM) estimates from the 1-year American Community Survey (ACS). This methodology would only use publicly-available data in order to be transparent and reproducible. Currently, the only sub-national SPM estimates available using 1 year of survey data are at the Public Use Microdata Area (PUMA) level and at the state level using 1-year ACS data. In this paper, county-level SPM estimates are produced from PUMA-level estimates using a county to PUMA crosswalk from the Missouri Census Data Center. There are three main types of county-PUMA relationships: counties that are exactly equal to a PUMA; counties that span multiple PUMAs; and PUMAs that span multiple counties. In the first case, the county-level estimates are exactly equal to the PUMA-level estimate. In the second case, the county-level estimate is a population-weighted average of the PUMA-level estimates. In the third case, the relationship between the official poverty measure (OPM) from the 5-year ACS at the county and PUMA level is used along with 2010 county populations to apportion the SPM population among counties within a PUMA. Several checks are performed in order to validate the PUMA to county methodology.