Small Business Investment Act of 2023

This bill modifies the tax exclusion for gains from qualified small business stock (QSBS), primarily affecting individual investors who sell stock in small businesses. It shortens the required holding period from five to three years, with exclusion percentages increasing to 50% after three years, 75% after four, and 100% after five or more years. The bill also allows the holding period of certain convertible debt instruments (that convert to QSBS) to count toward the stock holding period. These changes apply to stock acquired after the bill's enactment and aim to reduce capital gains tax liability for investors in qualifying small businesses.