Carson said he had only his suspicions to go on, but this year was the first time his taxes had been audited by the IRS and he added that the agency had tarnished its reputation for trustworthiness in an earlier scandal.
"We are in a situation where a government agency has been used to harass opponents of the administration, which places everything that the IRS does in a light of suspicion," Carson said in an interview Thursday. "So whether this is a massive coincidence or if I was targeted, it looks suspicious."
Carson acknowledged that "there's no way to know" whether he was targeted and that the IRS would probably not admit to it, anyway. But he said he wanted to speak publicly about the audit because he is also uneasy that the IRS will oversee the tax implications of the new health care law, which he opposes.
Carson has been in the media spotlight since he took aim at President Barack Obama at a prayer breakfast in February. The next month, he announced he would retire from his longtime post as director of pediatric neurosurgery at Johns Hopkins Hospital and has since made numerous appearances on conservative talk shows and launched a weekly column with the conservative-leaning newspaper The Washington Times.
The IRS could not be reached for a response to Carson's comments, as the agency's spokespeople have been furloughed amid the federal government shutdown this week.
Earlier this year, the IRS admitted it had targeted political groups for additional scrutiny of their tax-exempt status. While some left-leaning groups were identified for review, most were conservative. Top IRS officials and the Obama administration denounced the practice and placed the blame on a small group of lower-level staffers who appeared blind to the implications of their actions.
Carson said he thought the IRS controversy did not get enough media coverage and that it was worse than several other scandals, including the attack on the U.S. Consulate in Benghazi, Libya.
"This is a much bigger issue than Watergate," he said.
The "Gifted Hands" neurosurgeon is not the first to believe that an IRS audit stems from ulterior motives, though such charges are difficult to prove. Groups such as People for the Ethical Treatment of Animals, Code Pink and Greenpeace have complained they were targeted for audits under Republican administrations. In 2000, Maryland Gov. Robert L. Ehrlich Jr.'s chief fundraiser asked the IRS to investigate the NAACP's tax-exempt status.
Glen E. Frost, a Columbia-based tax attorney and certified public accountant, said many of his clients that have undergone audits this year have wondered whether they were somehow targeted.
"With all of the press and everything out there, I feel like that's just a natural reaction," he said. "People are looking for explanations."
Frost said the wealthy are more likely to be audited and that the IRS uses a special formula that calculates the risk of tax fraud. Certain charitable contributions, a large number of itemized expenses and a lot of business expenses that are not reimbursed can be red flags, he said.
Carson spoke about the audit at an appearance earlier this week in Alabama and on Wednesday on Fox News Channel's "The O'Reilly Factor."
Carson said he was notified in June that his taxes would be audited, and that his real estate holdings, joint tax return with his wife and prior year's returns were probed. He said that agents visited his offices at least once in June and concluded in August that his returns contained no mistakes or wrongdoing.