Angel Tax Credit Act - Amends the Internal Revenue Code to allow a new business-related tax credit for 25% of equity investments of $25,000 or more in a domestic corporation or partnership that: (1) has its headquarters in the United States, (2) has gross revenues for the taxable year of less than $1 million, (3) employs fewer than 25 full-time employees, (4) has been in existence for less than 7 years as of the date of the investment, (5) has more than 50% of its employees performing substantially all of their services in the United States, and (6) is engaged in a high technology trade or business. Limits the allowable amount of such credit to $250,000 in any taxable year and imposes an overall limitation on such credit of $500 million for each of calendar years 2013 through 2017.