Summary: Existing tax processing systems do not provide ready access to needed information or allow for modern work processes, a void the Internal Revenue Service (IRS) hopes to fill through its Tax Systems Modernization effort. IRS has requested a significant increase in spending for this program in fiscal year 1994. GAO has raised concerns about the appropriateness and the timing of much of this increase and questions the reliability of a $23 billion estimate made by IRS for the program. In addition, GAO believes that the program's success is at risk unless several problems are quickly resolved. For example, business studies that could significantly affect Tax Systems Modernization remain unfinished; the program lacks a firm management and technical foundation; and the program's human resource implications, including the need for new work force skills, need further consideration. Congress may want to consider requiring IRS to accomplish specific goals before releasing fiscal year 1994 appropriations or considering the fiscal year 1995 budget.