Incentivize Growth Now In Tomorrow's Entrepreneurs Act of 2013 - Amends the Internal Revenue Code to establish tax-exempt small business start-up accounts to provide for expenditures related to the creation or acquisition of an active trade or business. Limits the annual amount that may be contributed to such accounts to the lesser of $10,000 or the taxpayer's compensation that is includible in gross income. Sets forth reporting requirements for the trustee of a small business start-up account. Makes the tax penalties for prohibited transactions and excess contributions applicable to small business start-up savings accounts.