At a glance
- Employer contributions can be funded until Sept. 15, 2027 or Oct. 15, 2027, months after the plan must be established.
- A client who signs nothing by April 15, 2027 has no 2026 plan year and no deferral to work with; the next opening is likely the 2027 tax year.
- A client who signs in March still has until Sept. 15 or Oct. 15, 2027 to settle the employer contribution.
Sole proprietors can still open a 2026 solo 401(k) until April 15, 2027, with a $24,500 elective deferral ceiling.
Employer contributions can be funded until Sept. 15, 2027 or Oct. 15, 2027, months after the plan must be established.
A client who signs nothing by April 15, 2027 has no 2026 plan year and no deferral to work with; the next opening is likely the 2027 tax year. The April date is the one that has to be met either way.
A client who signs in March still has until Sept. 15 or Oct. 15, 2027 to settle the employer contribution. The deferral and employer contribution are separate pools: the deferral is the client's own money, the employer contribution comes from the business, and they can be decided on different dates.
One April deadline, two later funding dates
Solo 401(k) dates for the 2026 plan year, including the $24,500 deferral deadline
- Apr 15, 2027Plan must be established; $24,500 deferral decided (Current stage)
- Sept 15, 2027Employer contribution can be funded (Upcoming)
- Oct 15, 2027Later employer contribution funding date (Upcoming)
Show as table
| Date | Event | Detail |
|---|---|---|
| Apr 15, 2027 | Plan must be established; $24,500 deferral decided | |
| Sept 15, 2027 | Employer contribution can be funded | |
| Oct 15, 2027 | Later employer contribution funding date |
Reported by the Tax & estate planning desk from IRS 2026 elective deferral limit and solo 401(k) establishment deadline. Published . Corrections