For the past 22 years, Mrs. O contributed part of her salary to a retirement plan sponsored by her corporate employer. Under federal law, Mrs. O did not pay tax on the income she contributed. She will, however, pay federal income tax on the distributions from the plan when she retires. Mrs. O has resided in State A for her entire life. Because State A's personal income tax is based on taxable income for federal purposes, Mrs. O never paid State A tax on her retirement contributions. This year, Mrs. O retires and moves to State K, which has no personal income tax.