Romney released his 2011 tax return Friday, along with a summary of his 1990-2009 tax rates.
Brad Malt, an administrator for Romney's blind trust, said Mitt and Ann Romney owed state and federal income taxes in each of the last 20 years, Politico reported.
Malt said the average annual effective federal tax rate for the 20-year period was 20.20 percent and the lowest annual effective tax rate during the period was 13.66 percent.
"Over the entire 20-year period, the Romneys gave to charity an average of 13.45 percent of their adjusted gross income," Malt said.
"Over the entire 20-year period, the total federal and state taxes owed plus the total charitable donations deducted represented 38.49 percent of total [adjusted gross income]."
The Obama re-election campaign called on Romney to release the full returns "instead of the bare summary he has provided of the last 20 years, so voters can make their own judgments" about Romney's finances.
In a statement Friday, the Obama campaign said the release of Romney's 2011 return "confirms what we already knew -- that people like Mitt Romney pay a lower tax rate than many middle class families because of a set of complex loopholes and tax shelters only available to those at the top."
The Obama campaign said the release of the 2011 return "continues to mask Romney's true wealth and income from Bain Capital, leaving the American people in the dark about critical details about his finances [but] does confirm that he continues to profit from millions of dollars invested overseas."
The release of the 20-year summary follows debate within the Romney campaign about how much information to release and when to release it, Politico said, citing several sources.
The campaign said it will also release information on Romney's health and that of vice presidential nominee Paul Ryan.