Main Street Business Incentive Act of 1999

Main Street Business Incentive Act of 1999 - Amends the Internal Revenue Code (IRC) to accelerate, from taxable years beginning in 2003 to taxable years beginning after December 31, 1998, the $25,000 maximum dollar limitation applicable to the expensing of certain depreciable assets under section 179 of the IRC. Expands the definition of section 179 property (while maintaining the exclusion for air conditioning and heating units) to include any tangible property used in a trade or business.