President Obama's nominee for secretary of Health and Human Services, Gov. Kathleen Sebelius, failed to pay $7,918 in taxes and interest, she writes in a letter sent today to Senators Max Baucus and Charles Grassley.

According to Sebelius, an accountant who was hired to review tax returns for 2005, 2006, and 2007 discovered a number of errors. "In July of 2006, my husband and I sold our home for an amount less than the outstanding balance on our mortgage," Sebelius writes. "We continued paying off the loan, including interest we mistakenly believed continued to be deductible mortgage interest."

In addition to this error, there were three charitable contributions for which they "could not locate our acknowledgement letter." She adds she had "insufficient documentation" for some tax deductions for business expenses, though these adjustments did not affect the amount of tax owed because she paid the Alternative Minimum Tax.

Sebelius writes that she and her husband paid a total of $7,918 in back taxes and interest, but she does not say how much of that is owed due to the adjustments for charitable deductions and how much is owed because they erroneously deducted interest on their house loan.

Grassley and Baucus respond in a letter: "We would appreciate a response to this letter giving an account of the changes that were made in your amended returns."