I've had several instances where an individual has had several old retirement plans from previous employers.
That has included defined benefit plans, 401k's, TSP's, 403b's and Keough plans.
My personal faves for low costs are Vanguard and Trade King.
You only have to remember one website login and password to change investment choices.
Having the assets at one provider makes it easier to build a diversified portfolio.
Should I put all my retirement accounts with one brokerage/financial firm?
I have two accounts at one firm out of town, and a recently inherited account with another firm here in my hometown. My daughter will inherit it all, but she lives 10 hours away in another state with a family and responsibilities of her own.