AICPA American Institute of Certified Public Accountants CPA certified public accountant FASAB Federal Accounting Standards Advisory Board FASB Financial Accounting Standards Board GAAS AICPA's generally accepted auditing standards GAGAS generally accepted government auditing standards GASB Governmental Accounting Standards Board GAO General Accounting Office OMB Office of Management and Budget SASs AICPA's statements on auditing standards SSAEs AICPA's statement on standards for attestation engagements