10/23/2026
"How much can I put into my 401(k)?" Turns out there are two numbers, one that follows you and one that follows your employer. With one job, both still apply; there's usually just not much you can do about them. Add a side business you control, and the difference between them becomes room to work with.
The number that follows you is the employee deferral limit: $24,500 for 2026, plus catch-ups at 50+. It's per person, so two 401(k)s still share a $24,500 limit.
The second number is where it could get interesting. The overall contribution limit covers deferrals, the match, profit sharing, and after-tax contributions, and it's $72,000 for 2026. Unrelated employers generally each get their own.
This comes up a lot with clients who pick up consulting or maybe a passion that evolves into a business. If you've maxed your 401(k) at work and consult on the side, that business can open a solo 401(k) and make employer contributions, even with your (employee) deferral limit used up.
One catch (isn't there always?): for a sole proprietor, employer contributions top out around 20% of net self-employment earnings (after half the SE tax). A side business netting $50,000 might allow $9,000 to $10,000. A far cry from $72,000, but a few extra thousand a year, tax-deferred, is the kind of thing my Scottish ancestors would've walked uphill to collect.
A few things can wreck this. A 403(b) at your day job gets combined with plans from any business you control, so the two share one $72,000 limit. A solo 401(k) requires no eligible employees besides you and your spouse. And a SEP-IRA balance counts against backdoor Roth contributions; a solo 401(k) balance doesn't.
The IRS limit answers "how much can I contribute?" The details answer "how much can I save?"
