The Bureau of Labor Statistics is examining the feasibility of publishing Employer Identification Number (EIN)-level size class employment statistics. Estimates by size class are one of the most requested items to be published based on the Current Employment Statistics program. Producing monthly estimates by size class will allow data users to analyze the contribution to monthly employment numbers by small, medium, and large businesses. The estimates analyzed in this paper include periods of the most recent recession and the subsequent recovery. This paper discusses an updated methodology chosen for creating estimates by size class, the rationale of using a base-sizing definition, limitations associated with constructing a time series of over-the-month changes, and the insights gained from examining the results.