But the announcement today doesn't mean that name of the three-term incumbent will be taken off the ballot in New York, as the election laws in the Empire State would make that rather complicated.
One possible choice is for the state Republican Party to put Collins on the ballot in another race, as the Buffalo News reported that Collins' name could only be taken off the ballot by what the newspaper described as a "series of political maneuvers rarely – if ever – used in all of New York."
Before Wednesday's federal indictment, this seat in the Buffalo-area of western New York was considered very safe for Republicans - but obviously, the charges have changed that dynamic.
But, history shows it would not be out of the question for Collins to win re-election, even under the cloud of this indictment - just go back four years to the other end of New York, where Rep. Michael Grimm (R-NY) had been indicted on corruption charges - he won that race, but resigned his seat a few months later.
Democrats meanwhile called for Collins to quit.
"Speaker Ryan must call on Congressman Collins to resign," said House Democratic Leader Nancy Pelosi in a written statement. "No person is above the law, not the President or his first supporter in Congress."