"We request that the Treasury Department provide each of our committees with copies of all documents pertaining to the decision-making process… used in making the delisting determination," the letter said on Tuesday.
The letter, sent by Representatives Maxine Waters, Adam Schiff and Eliot Engel, requested that the documents be made available no later than February 5.
On Sunday the Treasury Department lifted sanctions against Rusal, EN+ Group and EuroSibEnergo after the three firms agreed to undergo structural changes that reduced Deripaska's interests.
Earlier US House Democrats said they are considering legislation to ensure that Russian businessman Oleg Deripaska does not benefit from the Treasury Department's decision. The lawmakers argued that they did not have a proper chance to review the documents.
The United States introduced sanctions against Deripaska and dozens of other Russian individuals and entities in April 2018 over their alleged links to the Russian government, which Washington accused of "malign activity." Russian Prime Minister Dmitry Medvedev said the United States was using a political tool to achieve economic goals.