The White House budget office launched USASpending.gov in 2007 to track federal spending after scores of lawmakers, including then-Sen. Barack Obama, successfully pushed through a bipartisan bill to ensure greater transparency with the funding.

At last check, less than 8 percent of the site’s spending information was accurate, and federal agencies had failed to report nearly $620 billion in grants, loans and other forms of assistance awards, according to a recent report from Congress’s nonpartisan Government Accountability Office.

The Federal Funding Accountability and Transparency Act of 2006, sponsored by Sen. Tom Coburn (R-Okla.) and signed into law by President George W. Bush, required the Office of Management and Budget to set up a Web site with data on federal awards and develop guidance on reporting requirements. President Obama later set a goal of 100 percent accuracy by the end of 2011.

But the legislation is not working as well as lawmakers and the administration had hoped. The GAO said a review of the 2012 data found “significant underreporting of awards and few that contained information that was fully consistent with the information in agency records.”

The findings drew criticism from members of the Senate Homeland Security and Government Affairs Committee, including Coburn, the panel’s ranking Republican.

Coburn said the reporting problems hinder Congress’s ability to determine the pros and cons of spending decisions.”It is disappointing that the federal bureaucracy is so vast and unaccountable that the administration cannot enact the president’s signature accomplishment as a senator requiring the government to disclose how and where it spends money,” he said in a statement on Monday.

Coburn used the GAO findings to tout legislation the House and Senate passed this year to require more-detailed reporting on federal spending. The bill, known as the DATA Act, was sponsored by Sen. Mark Warner (D-Va.), but it was molded after a similar measure in 2011 from Reps. Darrell Issa (R-Calif.) and Elijah Cummings (D-Md.).

Sen. Tom Carper (D-Del.), who heads the Senate committee, said Congress needs better spending data to make informed decisions.

“This latest GAO report underscores the federal government’s ongoing challenges when it comes to showing the American people how their tax dollars are being used, at what cost and with what result,” Carper said in a statement on Monday. “That’s why efforts like the DATA act are so important.”

OMB spokesman Jamal Brown said in a statement on Monday that the agency is committed to federal spending transparency and working with agencies to “improve the completeness and accuracy of data submissions to USAspending.gov.”

The GAO recommended that OMB develop a more-comprehensive oversight process for reporting information to the Web site and provide more-specific guidance on how agencies should validate their data.

OMB said in its response that it generally agrees with the suggestions, adding that the DATA Act already requires many of the recommended actions. The agency said it will work with the Treasury Department to consider interim steps that could improve data quality without interfering with its efforts to comply with the new law.