A trio of senators have proposed legislation targeting overseas tax havens. According to a bill summary released by Sen. Carl Levin, D-Mich., such havens cost the United States upwards of $100 billion a year in lost tax revenues.

“The eyes of some people may glaze over when tax shelters and tax havens are discussed, but unscrupulous taxpayers and tax professionals clearly see illicit dollar signs,” said Levin, in a statement summarizing the bill.

The bill would require hedge funds to establish programs to combat money laundering and better track offshore investors under guidance from the Treasury Department. It would also prevent the U.S. Patent and Trademark Office from issuing patents for accounting strategies intended to "minimize, avoid, defer, or otherwise affect liability for federal, state, local, or foreign tax."

The measure, co-sponsored by Sen. Norm Coleman, R-Minn., and Barack Obama, D-Ill., would impose more stringent requirements on U.S. taxpayers using offshore secrecy jurisdictions, give the Treasury the authority to take action against foreign jurisdictions that impede tax enforcement, stiffen penalties against abusers and close a number of offshore trust loopholes.

Similar bills have passed through the Senate, only to fail to make it out of committee in the House.