That’s what would happen under the Main Street Fairness Act (H.R. 5076). The measure would tax “qualified business income” of partnerships, S corporations, and sole proprietorships at a rate that is the same or lower than the rate for C corporations. The measure would not apply to capital gains. Caution: Don’t confuse this bill with another Main Street Fairness Act introduced in 2010 which related to sales tax on online sales.