The Democrat pledged to take the case to the U.S. Supreme Court if necessary, the Hartford (Conn.) Courant reported Thursday.
Blumenthal is challenging the way in which the school accountability law is funded. He argues that the law imposes costs on the state and towns that violate the act's prohibition against unfunded mandates.
Last month, U.S. District Judge Mark Kravitz in New Haven ruled there was no merit to claims by the state that U.S. Education Secretary Margaret Spellings erred when she denied a request to change testing procedures for children with limited English language skills, Legal Newsline reported.
The judge ruled there was no evidence the federal law violates one of its provisions against unfunded mandates.
The appeal was filed Wednesday with the U.S. 2nd Circuit Court of Appeals.
"The U.S. Department of Education has reneged in its responsibility to Connecticut students, failing to provide full federal funding to schools," Blumenthal said.