Forrester estimates that by 2027, US B2B e-commerce will reach $3 trillion and account for 24% of total US B2B sales. At the end of 2021, B2B e-commerce reached $1.7 trillion, representing 16% of total B2B sales in the US. We forecast a compound annual growth rate (CAGR) of 10.7% in B2B e-commerce over the next five years. This report outlines the potential of the US B2B e-commerce market across seller types and 11 durable and nondurable product categories, with historical data going back to 2008.