Known as the "extenders," the more than 50 expired tax laws are in limbo, waiting for Congress to decide whether to renew them or not. They range from tax breaks for multinational corporations to breaks for alternative energy and school teachers.
"The longer Congress delays action, the greater risk that the tax filing season and millions of taxpayer refunds will be delayed, among other serious disruptions," said Ron Wyden, the Democratic chairman of the Senate's tax-writing committee.
"As the economy begins to show signs of strength, uncertainty from the federal tax code is the last thing American businesses and families need," he said in a statement.
The extenders have been regularly renewed in past years. Wyden's committee in April approved legislation to keep the list of tax breaks alive through 2015, but the measure got bogged down in partisan squabbling earlier this year.