Base-Broadening Tax Act of 1984

Base-Broadening Tax Act of 1984 - Amends the Internal Revenue Code to provide for temporary reductions in certain income tax credits and deductions for taxable years beginning on January 1, 1985, and ending on December 31, 1989.

Provides for a ten percent reduction during such period of the amount of itemized deductions of an individual taxpayer.

Provides for a 20 percent reduction during such period of: (1) the foreign tax credit; (2) the credit for tax withheld on wages; (3) the earned income tax credit; (4) the credit for tax withheld at the source on nonresident aliens and foreign corporations; (5) the credit for certain uses of gasoline and special fuels; and (6) the Puerto Rico and possession tax credit.

Provides for a 20 percent reduction during such period of the income tax deductions for: (1) accelerated cost recovery; (2) the amortization of pollution control facilities; (3) circulation and research and experimental expenditures; (4) percentage depletion in excess of basis; (5) intangible drilling costs and mineral exploration and development costs; (6) certain financial institution preference items; (7) life insurance companies; and (8) capital gains.

Provides for a 20 percent reduction during such period of the dollar limitation on: (1) used property eligible for the investment tax credit; (2) the partial exclusion of dividends received by individuals; (3) the one-time exclusion of the gain on the sale of a residence; (4) the dividend reinvestment in stock of public utilities; (5) the exclusion of earned income of citizens or residents of the U.S. living abroad; (6) the deduction for certain depreciable assets; (7) the deduction for expenditures to remove architectural barriers to the handicapped and the elderly; (8) the deduction for amortization of reforestation expenditures; (9) the deduction for retirement savings; (10) the deduction for luxury cars; (11) benefits and contributions under employee benefit plans; (12) the amount of private activity bonds and mortgage subsidy bonds which may be issued under a State program; and (13) the deduction for net operating losses.

Sets forth definitions and special rules. Authorizes the Secretary of the Treasury to prescribe necessary regulations.