Production of oil and natural gas from leased federal lands and waters is a significant source of revenue for the federal government. The Government Accountability Office (GAO) has issued many reports on Interiors management of federal oil and gas resources, including its programs for verifying oil and gas production volumes and ensuring accurate royalty collections. These reports raised questions about whether the government was collecting all the revenue it was due and included 36 recommendations to strengthen royalty collection, among other things. In 2011, GAO added Interiors management of federal oil and gas resources to its list of programs at high risk of fraud, waste, abuse, and mismanagement. This book examines efforts Interior has taken since fiscal year 2009 and the reasonableness and completeness of Interiors royalty data. The book also assesses the extent to which Interior's production verification regulations and policies provide reasonable assurance that oil and gas are accurately measured; the extent to which Interiors offshore and onshore production accountability inspection programs consistently set and meet program goals and address key factors affecting measurement accuracy; and Interiors management of its production verification programs. Finally, it provides a descriptive update on Interiors Minerals Management Service's (MMS) key efforts to improve the accuracy of oil and gas royalty data; the assessment of the completeness and reasonableness of fiscal years 2006 and 2007 oil and gas royalty datathe latest data available; and factors identified by oil and gas companies that affect their ability to accurately report royalties owed to the federal government.