To amend the Internal Revenue Code of 1986 to extend expiring provisions, to fully allow the nonrefundable personal credits against regular tax liability, and for other purposes.

Title I: Extension of Expiring Provisions - Amends the Internal Revenue Code to allow an individual to offset the individual's entire regular tax liability, without regard to the minimum tax, by the personal nonrefundable credits (including the dependent care credit, the credit for the elderly and disabled, the adoption credit, the child tax credit, the credit for interest on certain home mortgages, the HOPE Scholarship and Lifetime Learning credits, and the District of Columbia homebuyer's credit ).(Sec. 101) Repeals the requirement that reduces the refundable child credit by the amount of an individual's minimum tax.(Sec. 102) Extends from June 30, 1999, through June 30, 2004, the tax credit for increasing scientific research activities. Revises the alternative incremental research credit rate by specified percentage increases in components of the rate formula.Declares that the allowable research tax credit attributable to the period from June 30, 1999, through September 30, 2000, (suspension period) shall not be taken into account before October 1, 2000. States that on or after October 1, 2000, such credit may be taken into account through the filing of an amended return, an application for expedited refund, an adjustment of estimated taxes, or other means allowed. Provides for an expedited refund of any tax overpayment resulting from such treatment of the research tax credit, if the refund application is filed before October 1, 2001. Waives estimated tax penalties for any period before June 30, 1999, for any underpayment of tax created or increased by reason of the treatment of the research tax credit by this Act.(Sec. 103) Extends from January 1, 2000, until January 1, 2005, the subpart F exclusion of active banking, financing, or similar income from taxable foreign personal holding company income, insurance income, and foreign base company services income to which ten-percent U.S. shareholders of a controlled foreign corporation are subject regardless of whether such income is distributed to them.(Sec. 4) Extends from January 1, 2000, until January 1, 2005, suspension of the 100-percent-of-net-income limitation on the deduction for percentage depletion from marginal oil and natural gas wells.(Sec. 5) Extends from June 30, 1999, through December 31, 2001, the work opportunity tax credit (WOTC) (equal to a specified percentage of qualified first-year wages paid to individuals hired from one or more specified target groups) and the welfare-to-work tax credit (equal to a specified percentage of the first $20,000 of eligible wages paid to qualified long-term recipients of family assistance under part A (Temporary Assistance for Needy Families) (TANF) of title IV of the Social Security Act).Revises the exclusion from qualified first-year wages for WOTC purposes of any wages paid to an individual if, before the hiring date, such individual had been employed by the employer at any time during which he or she was not a member of a targeted group. Repeals the limitation of the exclusion to individuals previously employed while not a member of a targeted group (thus excluding the wages of previously employed individuals even if they were members of a targeted group during the previous employment).Title II: Other Time-Sensitive Provisions - Treats any advance pricing agreement entered into by a taxpayer and the Secretary of the Treasury, and any related background information, or any application for such an agreement, as confidential taxpayer information. Requires the Secretary to report annually on advance pricing agreements, omitting any information that would identify particular taxpayers.(Sec. 202) Adds conjugate vaccines against streptococcus pneumoniae to the list of vaccines subject to a certain sales tax, but only if the Centers for Disease Control make a final recommendation for routine administration to children of any such vaccine.Amends the Vaccine Injury Compensation Program Modification Act to: (1) remove vaccines against rotavirus gastroenteritis from the list of taxable vaccines; and (2) repeal authority for payment from the Vaccine Injury Compensation Trust Fund of unlimited Federal expenses for administration of compensation for vaccine-related injury or death (but retain the otherwise mandatory limit on payable expenses of $9.5 million per fiscal year). Repeals the prohibition against appropriations to the Trust Fund that are not specifically permitted by the Code provision establishing the Fund. Changes from August 5, 1997, to October 21, 1998, the effective date of certain authority for the payment of vaccine injury compensation from the Trust Fund.Requires the Comptroller General to report to specified congressional committees on the Trust Fund's operation and adequacy to meet future claims.(Sec. 203) Authorizes the Secretary to disregard a period of up to 90 days in determining, in respect of any tax liability of any taxpayer affected by a Y2K failure: (1) whether certain tax compliance, assessment, or collection acts were performed by specified deadlines; and (2) the amount of any credit or refund due.Title III: Revenue Offset - Revises the modified safe harbor from the additional tax for underpayment of the estimated tax of an individual with an adjusted gross income of more than $150,000. Increases from 106 percent to 108.5 percent of the preceding taxable year's income the percentage of income for the taxable year beginning in 1999 which the individual is required to pay in estimated taxes for a taxable year beginning in 2000.