Individual 401K / Self-employed 401K

[RiskDown]

I am setting up an Individual/Self-Employed 401K. It appears Vanguard does not have them as an option (they send you to a third party named Ascensus).

I would appreciate any recommendations, especially ones which allow you to invest in Vanguards core funds at lowest fees.

[sonofsven]

I procrastinated and mine moved from Vanguard to Ascensus. They charge $20/yr.
Fidelity is the best choice going forward.

[MDM]

Solo 401(k) plan - Bogleheads offers some references that may help you.

[yachi]

Mr Money Mustache himself had poor things to say about Ascensus on the platform formerly known as Twitter:

WOW. I finally got around to transferring my biggest 401k out of
@AscensusInc
 , and should have done it long ago!

Backstory:
@Vanguard_Group
 got out of the business of offering employer 401ks last year, unfortunately. But I trusted them enough to leave my account invested with the new company they moved us all to. Bad idea.

Not only does Ascensus have high recurring fees, the web interface is also incredibly clunky, customer service phone line had a 19-minute wait, and after all that they tell me they *DON'T SUPPORT ELECTRONIC TRANSFERS OF YOUR MONEY!!!*

So in order to move my account, they are going to sell hundreds of thousands of dollars of my index funds, print a PAPER CHECK, then MAIL IT to my new brokerage (Schwab), where they will have to re-purchase the index funds at an entirely new price (possibly tens of thousands of $$ lost) due to market volatility.

This is the worst investment account experience I've ever seen. Yes, it's still a rich world problem, but I highly recommend staying away from this company.

and this:

Update: apparently the main reason they can't do in-kind transfers is that they are not a real broker, just a caretaker of your account.

If true, it makes sense to keep your 401k somewhere that has a full brokerage (and you can even check in advance that they allow electronic transfers out if you ever need to close the account)

[Archipelago]

I've had a Solo 401(k) aka Keogh with Fidelity for over 6 years now. I've had nothing but good experiences with it. Do note they do not have electronic transfers / automated investing. So you have to mail checks and a contribution remittance form when you want to make contributions. That's the only downside. Outside of that, they have access to the same low cost or zero cost index funds that Vanguard has. And no annual fees either.

[WorkingToUnwind]

I have a self-employed 401k through Fidelity and it's all electronic make bank transfers and purchases.

[terran]

I've had one with Fidelity that I moved to E*Trade several years ago and have now closed as of just a few days ago for unrelated reasons.

Fidelity was good except you had to mail in contributions for visit an office (that might have changed) and they didn't allow Roth contributions, which also might have changed. I have other investments with Fidelity, so I wouldn't hesitate if those two things have changed since I last had a solo 401(k) there. Really the Roth option was the only reason I moved.

I never had a problem with E*Trade, they allow Roth contributions and in-plan Roth conversions of past traditional contributions. I haven't seen any ill effects of the Morgan Stanley merger, although it's something I'd keep an eye on. Since the merger they've introduced some low/no fee mutual funds, so I'm guessing Morgan Stanley bough E*Trade to compete in the budget broker space.

If I was opening a plan today I'd also look at Schwab, which I think I saw allows Roth contributions.

Make sure you understand the form 5500 filing requirements.