Can an llc owner contribute to a 401(k), even without employees?

Yes, you can. Look into a solo 401(k) or individual 401(k). As long as you have no employyees other than yourself (and maybe a spouse), you're eligible. You can contribute as both employee and employer.

Wait, does the LLC being disregarded matter? I thought you need to be a sole proprietor or partnership. But I guess a single-member LLC is treated as a sole prop for for tax purposes, so it should be fine.

Yep, solo 401(k) is the way. But keep in mind the contribution limits: for 2023, employee deferral is $22,500 (plus $7,500 catch-up if 50+), and employer profit-sharing up to 25% of compensation. Total cap is $66,000 (or $73,500 with catch-up).

Just don't forget about the paperwork. There's Form 5500-EZ once assets hit $250k. And make sure you actually have net self-employment income.

So if I have a full-time job with a 401(k) and also a side LLC, can I still do a solo 401(k)? I'm confused about the employee deferral limit across plans.

That's a good question. The employee deferral limit is per person, not per plan. So if you max out your day job's 401(k), you can't defer more from your side gig. But you can still do employer contributions from the LLC

Also, if you have employees in the future, the solo 401(k) gets complicated. But for now, it's perfect for a one-person LLC. Just open one with a brokerage like Fidelity or Schwab.

Oh great, another retirement account to keep track of. But seriously, solo 401(k) is a no-brainer if you're self-employed. Just don't expect to contribute more than you earn.

I set up a solo 401(k) for my single-member LLC last year. It was surprisingly easy. Vanguard has a good option. Just make wure you have an EIN for the plan.