The Census Bureau has released the 2013-2017 American Community Survey (ACS) 5-year Public Use Microdata Sample (PUMS) files and Variance Replicate Estimate Tables.
The ACS 5-year PUMS files show the full range of population and housing unit responses collected on individual ACS questionnaires for a subsample of ACS housing units and group quarters persons (approximately five percent of the United States population).
PUMS files allow data users to conduct a custom analysis, though the files also tend to be more complicated to use. Working with PUMS data (scheduled release: Feb 14) generally involves downloading large datasets onto a local computer and analyzing them using statistical software such as R, SPSS, Stata, or SAS.
The 2013-2017 ACS Variance Replicate Estimate Tables allow advanced users to calculate margins of error (MOEs) when collapsing data within a table or across geographies - a more accurate MOE than available approximation formulas.