The BLS Current Employment Statistics (CES)1 program recently introduced experimental employment data by firm size2. This data offers an additional level of detail beyond industry level and allows for greater understanding of employment trends. Foremost, users will be able to analyze current and historical employment changes by firm size, including how employment in firms of different sizes behaves around cyclical turns in the economy. But, there are other analytical uses for the series. For example, not all employment is distributed by firm size in the same way across industries. Firm size employment data can also reveal differing patterns of job growth or loss within industries. In addition, a breakdown of employment data by firm size can reveal patterns of varying seasonal build up and layoff within industries.