Government Regulatory Improvement and Performance Act of 1998 - Declares that:  (1) Federal agencies should promulgate only such regulations as are required by law, necessary to interpret the law, or necessary to protect and promote or improve the health and safety of the public, the environment, or the well-being of the American people; and (2) in deciding whether and how to regulate, agencies should assess all costs and benefits of available regulatory alternatives, including the alternative of not regulating. 
Sets forth principles of regulation to ensure that the agencies' regulatory programs are consistent with such philosophy, including that each agency:  (1) identify the problem that it intends to address by regulation, assess its significance, and if possible conduct a risk analysis; (2) identify and assess available alternatives to direct regulation; (3) wherever feasible, seek views of appropriate State, local, and tribal officials before imposing requirements that might significantly or uniquely affect those governmental entities. 
(Sec. 3) Directs the Office of Management and Budget to carry out coordinated review of agency rulemaking.  Designates its Office of Information and Regulatory Affairs (OIRA) as the repository of expertise concerning regulatory issues. 
(Sec. 4) Directs the OIRA Administrator, early in each year's planning cycle, to convene a meeting of the regulatory policy advisers to the President and agency heads to seek a common understanding of priorities and to coordinate regulatory efforts for the upcoming year. 
Requires each agency to prepare:  (1) a unified regulatory agenda of all regulations under development or review; and (2) a regulatory plan of the most important significant regulatory actions that the agency reasonably expects to issue in that fiscal year or thereafter. 
Directs the Administrator to:  (1) convene and chair a regulatory working group, which shall meet at least quarterly, to assist agencies in identifying and analyzing important regulatory issues; (2) meet quarterly, along with agency heads, with representatives of State, local, and tribal governments to identify exiting and proposed regulations that may uniquely or significantly affect those governmental entities; and (3) convene periodic conferences with representatives of businesses, nongovernmental organizations, and the public to discuss regulatory issues. 
(Sec. 5) Requires that:  (1) each agency submit to OIRA a program under which the agency will periodically review its existing significant regulations; and (2) any significant regulations selected for review be included in the agency's annual plan, and the agency identify any legislative mandates that require the agency to promulgate or continue to impose unnecessary or outdated regulations. 
(Sec. 5) Requires each agency to:  (1) submit to the OIRA a program under which the agency will periodically review its existing significant regulations for possible modification or elimination; (2) provide the public with meaningful participation in the regulatory process and a meaningful opportunity to comment on any proposed regulation, generally including a comment period of not less than 60 days; and (2) explore and, where appropriate, use consensual mechanisms for developing regulations, including negotiated rulemaking. 
Directs:  (1) each agency head to designate a Regulatory Policy Office; (2) each agency to develop its regulatory actions in a timely fashion and adhere to specified procedures; (3) each agency to provide the OIRA with a list of its planned regulatory actions, including significant regulatory actions; and (4)  the Administrator to provide meaningful guidance and oversight. 
(Sec. 8) Prohibits an agency from publishing a regulation until the Administrator has waived review of the action, completed such review, or the review period has passed, whichever occurs first.
Output: Government Regulatory Improvement and Performance Act of 1998