Grand Portage Band Per Capita Adjustment Act - Amends the Indian Tribal Judgment Funds Use or Distribution Act to exclude funds paid by Minnesota to members of the Grand Portage Band of Lake Superior Chippewa Indians, pursuant to the agreements of such Band to voluntarily restrict tribal rights to hunt and fish in territory ceded under the Treaty of September 30, 1854, from: (1) federal or state income taxes; or (2) use in denying or reducing a member's benefits under the Social Security Act or, except for payments in excess of $2,000, a federal or federally-assisted program.