Can you take your 401k from your old job and just roll it over/merge/combine/transfer it to the 401k at your new job? I always assumed this was the logical thing people did, but it doesn't seem to be that common? Do you roll it into an IRA and just let it sit there til you retire and start your new 401k from scratch? I am changing jobs and this is the first time I will be dealing with this, but I don't trust my current HR person to give me correct information based on past precedent. Ideally I would like to just transfer it to my new job's 401k and keep the train rolling.