Series of investigations
The targeting scandal and a separate inspector general's report that documented wasteful spending on IRS conferences in past years have led to a series of investigations of the tax collection agency by Congress, the Department of Justice, the tax administration inspector general's office and Werfel.
The IRS admitted there was unfair targeting of conservative groups seeking tax-exempt status starting in 2010, but officials said the action was a bureaucratic shortcut in its Cincinnati office rather than an exercise of political bias.
In his report that disclosed the misconduct, George said there was no evidence of a political motive. However, George is continuing to investigate the matter, along with the FBI and the congressional committees.
Republicans argue the controversy is proof that the administration and progressive groups have been trying to clamp down on those who disagree with Obama's agenda.
Camp, a Michigan Republican, said Monday that the IRS "still needs to provide clear answers to the most significant questions -- who started this practice, why was it allowed to continue for so long, and how widespread was it?"
"This culture of political discrimination and intimidation goes far beyond basic management failure and personnel changes alone won't fix a broken IRS," Camp said in a statement that promised continued investigation.
As part of his review, Werfel said 80 groups awaiting IRS action on their applications for tax exempt status for more than 120 days could self-register with the agency as long as they certified under penalty of perjury that they would comply with applicable laws and regulations.
At the heart of the matter is what kind of organization can qualify for tax-exempt status. Regulations limit such status to groups primarily involved in social welfare activities, while political groups are considered ineligible.
Confusion over defining what constitutes political activity versus social welfare activity contributed to the targeting by the IRS, Werfel said.
An IRS statement on Monday said the "safe-harbor" option for self-certification would apply to groups that "certify they devote 60% or more of both their spending and time on activities that promote social welfare."
"At the same time, they must certify that political campaign intervention involves 40% or less of both their spending and time," the statement said. Applicants meeting those thresholds would get approval within two weeks of seeking self-certification, it said.
Werfel said the IRS would continue checking on tax-exempt groups to ensure they were following the law.