10/23/2026
"We'll set up the 401(k) later." Later has a deadline.
It's different for every plan. A 401(k) has to exist by December 31 to count for 2026 (you can fund it after year-end, but there's no retroactive plan). A SEP can be opened as late as your tax filing deadline, extensions included. A new SIMPLE generally had to be in place by October 1, which has already passed for 2026.
So "later" means three different things, and picking the wrong one can cost you a full year of contributions at exactly the income level where they matter most.
If a new plan is on your list, DM me. I'll tell you straight whether the calendar still works for 2026. (Then talk to your tax advisor about getting it done.)