Where can I find a Third Party Administrator for a self-directed solo 401K?
You setup a self-directed solo 401k by paying a one time fee for a company to setup a trust, name you the sole trustee, and file it with the IRS. None of these companies offer TPA because it opens them up to profit leaching liability. After you have your trust setup, you can open a brokerage account or several with any of the big names you want (Vanguard, Fidelity, Ameritrade, etc), or just use the money to flip houses, do P2P lending, whatever, the world is your investment oyster. If the company has recurring fees you need to ask what is going on because if they aren't offering TPA services, then what the heck could they be charging you for? I did see one company, I think it was IRA Financial Group, that had the option of having a CPA do TPA for you for a recurring fee, but I would pass on that. The IRS administration requirements are typically just the 5500-EZ that you have to file as a hard copy by July 31 if your investments are worth more than $250k, on December 31. Yes, you have to get the actual form from the IRS, write on it with a pen and mail it to them every year, barbaric. You can either have your accountant do it or do it yourself. If you're below $250k just google solo 401k rule change two or three times a year and don't try to launder money. If anything, the rules will loosen with time, I don't imagine the Republican Congress cracking down on small business owners any time soon.