Pelosi said the decision on whether to initiate the process will fall to the Ways and Means Committee.
Rep. Richard E. Neal (D-Mass.), who is expected to become chairman of the tax panel, has said he plans to insist that Trump release his tax returns.
If Trump doesn’t do so voluntarily, then Neal plans to file a legal request with the treasury secretary that would require that the returns be disclosed to a small group of people on Capitol Hill. Neal has predicted that the matter would end up in federal court.
Trump has continued to resist releasing his returns, claiming they are under audit.
Democrats have said they want to scrutinize Trump’s tax returns to see whether he has any conflicts of interest. The inquiry could tie in to a broader investigation into any connection between Trump’s presidential campaign and Russian involvement in the 2016 election — an allegation the president has repeatedly and vehemently denied.
There is a long-standing tradition of presidents and presidential candidates releasing their tax returns, but Neal acknowledged that the Treasury Department might not provide the information quickly, setting up a legal battle.
Pelosi had previously said that seeking Trump’s tax returns would be one of the Democratic-led House’s priorities.
Erica Werner and Damian Paletta contributed to this report.