The rights of retirement plan participants to receive information about their plans on paper needs to be strengthened and protected, the General Accountability Office, the investigative arm of Congress, said in a study Tuesday.

“Paper disclosures continue to play an important role in meeting the needs of those not connected to the Internet or who prefer paper, and in helping locate participants when e-mail communications are returned as undeliverable,” the report said.

The GAO urged the Labor and Treasury departments to consider requiring plan sponsors to let participants opt out of all forms of electronic delivery, including disclosures sent by default through e-mail and on the Web.

It’s hard for many participants to get plan information without using e-mail and the Web because they must request paper on a document-by-document basis, GAO noted.