Senate passage sends the bill to the White House for President Obama's signature into law.
Delaying the requirement until next April will allow for the completion of a study into whether making financial disclosure forms public would pose any risks to the government or its workers. The study was required in legislation passed in September, which also delayed the deadline until Dec. 8, 2012.
President Obama is expected to sign the new bill into law either today or Friday, before the Dec. 8 deadline takes effect.
The House approved H.R. 6634 on Wednesday, also with no debate.