The initial plan is to spend time with his family. Romney has five adult sons and 18 grandchildren; a 19th is on the way.
His wife, Ann, recently said her husband absolutely will not run again for president. If he did, it would be his third time.
Senior Romney advisers refused to speculate publicly about what the future might hold for their longtime boss.
There was a general consensus that the 65-year-old former Massachusetts governor was unlikely to disappear from the public eye altogether. But what future role he would play in a fractured Republican Party remained unclear.