Judge Ambro has announced that he will take senior status, effective upon the confirmation of his successor. He is the third judge to do so during the term of President Biden (the others are Chief Judge Smith and former Chief Judge McKee), which enables the President to nominate a new judge to fill Judge Ambro’s seat. President Biden has not yet nominated anyone to fill the seats of Judges McKee and Smith, so there are three slots to be filled.
Judge Ambro is from Delaware. So it is to be expected that his successor will also be from the First State, which is also President Biden’s home state.