A day before he was to appear at a congressional hearing focused on the biggest banks in the United States, Bank of America’s chief executive, Brian Moynihan, said on Tuesday that the bank planned to raise its minimum wage to $20 an hour from $15 over the next two years.

It was another example of how big banks are trying to deal with shifting political winds in Washington, where they face new scrutiny under the Democrats, who now control the House of Representatives.

Income inequality has become a key focus of some liberal lawmakers, some of them part of the tide of Democrats swept into office in last year’s midterm elections. And now the banks’ leaders must explain to progressive representatives like Maxine Waters of California and Alexandria Ocasio-Cortez of New York why they are paid more than 700 times what low-wage workers, including some tellers in their branches, earn each year.

Appearing on the MSNBC show “Morning Joe,” Mr. Moynihan said that starting next month, Bank of America’s lowest-paid employees would earn $17 an hour. The hourly rate would increase incrementally over the next two years until it reached $20, the highest minimum wage paid by any of the country’s largest banks.