I don't know whether or not you can withdraw funds from an employer 401(k) while you're still employed and/or contributing. I'm guessing that varies a lot from plan to plan, and that there are a lot of factors to consider, for example if it affects an employer match. If I were you, I'd check with your benefits administration department or HR. One thing you might check is, since you're happy with Vanguard as your funds manager, is if you can withdraw funds from the company 401(k) and retain Vanguard as the funds manager.I fear that aggregating the old company 401(k) with the Rollover IRA will make eventually withdrawals from that IRA a nightmare because the source contributions spread across very different periods and factoring the tax will be complex. In your opinion (you are not being QFT), is that fear justified? I would prefer to simplify but, like I said, I worry.