Andrew Olmem, who until recently was a Washington-based partner at the law firm Venable L.L.P., is a special assistant to the president for financial policy after he lobbied the federal government on behalf of a number of financial firms, including American Express, MetLife and S&P Global. Mr. Olmem’s waiver allows for him to participate in communications and meetings with former clients involving Puerto Rico’s financial issues, as well as amendments to the Flood Disaster Protection Act and reforming the Financial Stability Oversight Council’s treatment of insurers, the White House said.

A second waiver was given to Michael Catanzaro, who until January was registered as a lobbyist for companies including Devon Energy, an oil and gas company, and Talen Energy, a coal-burning electric utility. Mr. Catanzaro moved from lobbying against Obama-era environmental rules to overseeing the White House office in charge of rolling back the same rules, an activity permitted by his waiver.

Also receiving a waiver was Shahira Knight, who had been a lobbyist for Fidelity Investments and now serves as a special assistant to the president for tax and retirement policy — the same topic she had lobbied on while working for Fidelity, one of the largest retirement-investment companies in the United States.

Five former lawyers and another former employee from Jones Day — the law firm that handled compliance matters and other legal issues for the Trump campaign — also have been given waivers to communicate with the firm. Donald F. McGahn II, the White House counsel, is one of the former Jones Day lawyers covered by that waiver.

The waivers made public Wednesday also appear to retroactively eliminate an apparent ethics problem for Stephen K. Bannon, the president’s chief strategist, who was an executive at Breitbart News. The ethics policy prohibited him from contacting employees at Breitbart for two years on matters he had handled while an executive there, but Mr. Bannon repeatedly engaged in conversations with Breitbart editors, according to a complaint filed by the liberal Citizens for Responsibility and Ethics in Washington.