The funds will remain frozen until the Defense Department addresses concerns about the cost and feasibility of the move, Sen. Jim Webb, D-Va., said in a statement to Stars and Stripes.
"It is premature to assess the accuracy of what the Defense Department describes as preliminary cost estimates for realignment actions on Guam," Webb said.
Congress gave the department until the end of next month to submit an independent study on the base realignment and possible alternatives.
A preliminary cost estimate of $8.6 billion for the move isn't based on any specific military construction projects on Guam, and the Government Accountability Office determined last year the cost would likely be closer to $23.9 billion, Stars and Stripes said.
Under an agreement released last month, 9,000 Marines are to be transferred off Okinawa to Guam, Hawaii and Australia.
The U.S. portion of the $8.6 billion move to Guam would be $5.8 billion and Japan has agreed to pick up $2.8 billion, the country's Ministry of Defense said.
Navy Capt. Dan Cuff, forward director of the Joint Guam Program Office, said the Navy needs to do a study to determine needs for Marine Corps bases, housing and training areas and where they'll be located.