Freelancer Retirement Deadlines and Catch-Up Contributions After 50 (US)

DRAFT — NOT CPA/LEGAL-REVIEWED — in Compliance HOLD until a qualified CPA/legal reviewer is engaged; do not describe as reviewed.

Educational only. This guide explains a system; it is not personal advice for your situation. Before you act on any tax or retirement figure here, consult a tax professional.

Short answer: The deadline that costs freelancers the most money is the one they never heard of: a Solo 401(k) must be established by 31 December for its employee deferrals to count for that year, while a SEP IRA can be both established and funded up to your tax-filing deadline with extensions. Miss the December date and a year's deferral room is gone for good — no extension rescues it. After 50, the Solo 401(k) also opens catch-up room the SEP never offers: an extra $8,000 at age 50+ for 2026, and $11,250 at ages 60–63. This guide is US-only, and it is about dates and age-based limits only — the account comparison is Guide C1, the saving rate is Guide C2, and the year-round timing calendar is Guide C4. Consult a tax professional before acting on any deadline in this guide, because a missed deadline is not fixable by good intentions.

Who this is for: A US freelancer who is either (a) near year-end and wondering what is still open for last year's income, or (b) aged 50 or over and wondering what extra room the law allows — or both, since December and age 50 have a habit of arriving together.

Who this is not for: Anyone looking for investment picks, for a recommendation between a SEP and a Solo 401(k) on grounds other than deadlines and catch-ups, or for advice about a work plan with employees. The hiring note at the end of this guide is a warning, not a workaround.

The deadline asymmetry, stated plainly

Here is the table freelancers actually need, for tax year 2026. Keep it somewhere you will see it in November, not in April:

Read that table twice, because the asymmetry is the whole story. The Solo 401(k) splits in two: its deferral half is a December deadline, its employer half is a filing-deadline-plus-extensions deadline. The SEP does not split at all: establishment and funding share the later deadline. The personal IRA sits in between in one respect — its deadline is the filing deadline, but extensions do not move it, unlike the SEP.

A concrete example makes the cost real. Take a fictional freelancer, Daniel, who earns $90,000 of net profit in 2026 and does nothing about retirement until February 2027, when his tax return is being prepared:

• If Daniel had a SEP IRA (or opens one now): he can still establish it and fund it for 2026, up to the filing deadline with extensions, subject to the SEP maths (effectively 20% of plan compensation — see Guide C1). February is not too late.
• If Daniel had no Solo 401(k) in 2026: he cannot create 2026 deferral room in February 2027. The $24,500 deferral for 2026 (under 50) is gone. He can still open a Solo 401(k) for 2027 and use its employer contribution for 2026 only if a plan existed in time — which, in this example, it did not. The February discovery costs him a full year's deferral.
• If Daniel had a Solo 401(k) established by 31 December 2026: the deferral window for 2026 has still closed in the sense that deferrals are made during the year, but the employer contribution for 2026 remains open to the filing deadline with extensions. Half the plan's room survives February; the other half does not.

That is why Guide C4 schedules its annual true-up in early December. A true-up done in April can only use the doors that are still open. A true-up done in December can use all of them.

What "filing deadline with extensions" actually means

For a sole proprietor, the tax-filing deadline for the year is generally mid-April of the following year, and a timely filed extension moves the filing deadline — and, for SEP and Solo employer contributions, the contribution deadline — to mid-October. Two cautions:

1. The extension must actually be filed, on time. An assumed extension is not an extension. If no extension was filed, the April date stands, and an October contribution designated for the prior year is simply late.
2. Extensions do not move every deadline. As the table above shows, a personal IRA contribution deadline does not move with an extension, and a Solo 401(k) deferral deadline does not move at all — it is a December deadline, full stop. "I filed an extension" is therefore not a general answer to "am I too late?" It is an answer for SEP contributions and Solo employer contributions only.

If any of this feels uncertain for your filing status or entity type — a single-member LLC taxed differently, a partnership, a spouse on payroll — that uncertainty is exactly what a tax professional resolves. Entity details change deadline mechanics, and this guide is written for the common sole-proprietor case, not as a substitute for advice on yours.

Catch-up contributions after 50: Solo yes, SEP no

The second half of this guide is shorter, because the rule itself is short: only the Solo 401(k) offers catch-up contributions. A SEP IRA has no catch-up contributions at all, at any age.

For 2026, per IRS Notice 2025-67, the Solo 401(k) catch-up figures are:

Check the arithmetic on the 60–63 row, because it is the row people misread: $24,500 + $11,250 = $35,750 of deferral, and $72,000 + $11,250 = $83,250 of total plan contributions. The $11,250 figure is the enlarged SECURE 2.0 catch-up for ages 60–63 only — it is not a new permanent catch-up for everyone over 60. At 64, the catch-up falls back to $8,000. A freelancer who turns 60 in 2026 gets the $11,250 window for 2026; a freelancer who turned 64 in 2026 does not.

A worked example, fictional, at age 62: a freelance consultant, Elena, has $120,000 of net profit in 2026 and a Solo 401(k) established well before year-end. Her maximum, in outline, is a $35,750 deferral (including the $11,250 catch-up) plus an employer contribution computed on plan compensation — effectively 20% of plan compensation, as in Guide C1 — up to the $83,250 total cap. The cap, not the deferral, is what binds at higher incomes: at very high profits, Elena's deferral plus employer maths would exceed $83,250, and the cap cuts it back. At lower profits, earnings and the deferral limit bind first. Either way, the catch-up is extra deferral room, not extra employer room — it raises the deferral and the total cap by the same amount, and it does not change the 20% employer maths.

Two further points on catch-ups, both easy to miss:

• Catch-ups need a plan that allows them, and a deferral to attach to. You cannot contribute a catch-up to a SEP IRA, and you cannot contribute a catch-up to a Solo 401(k) that was never established. The December establishment deadline therefore matters even more after 50: it is the door to the catch-up room itself.
• Catch-up limits change annually, like all limits. The $8,000 and $11,250 figures here are 2026 figures, checked 25 Oct 2026. In a later year, verify that year's figures before contributing — and note that the 60–63 window is age-based, so a birthday can change your limit more than inflation does in a given year.

The hiring blocker: when a Solo 401(k) ends

A Solo 401(k) is an owner-only plan. The moment a freelancer hires a full-time employee who is not their spouse, the Solo 401(k) as an owner-only plan generally ends — it cannot simply carry on as before with employees added on the side. That is not a paperwork nuisance; it is a plan-eligibility change, and it can arrive in the same year as a December deadline or a catch-up decision.

What this means in practice:

• Before hiring, check the plan consequences. Talk to a tax professional before the first employee's start date, not after the first payroll run. The choice of replacement plan, and the timing of the switch, affects which contributions are still possible for the hiring year.
• A SEP handles employees differently — and not freely. A SEP requires the same contribution percentage for eligible employees (generally age 21+, worked 3 of the last 5 years, earned at least $800 in 2026) as for the owner. Hiring does not "solve" the Solo problem by switching to a SEP without cost; it replaces one constraint with a different, potentially expensive one. Guide C1 covers the SEP employee rule in full.
• Do not let a hiring year become a lost retirement year by accident. The year a business hires is precisely the year retirement saving is most likely to be forgotten, because payroll, onboarding, and client work crowd it out. Put the plan review on the hiring checklist itself, in the same week as the offer letter — not on a "later" list.

This note is deliberately brief: hiring changes plan eligibility, and eligibility changes are professional-advice territory. What this guide guarantees is that you will not be surprised by the existence of the blocker. What it does not do is tell you which replacement plan to choose.

A December checklist (use it every year)

• Solo 401(k) established by 31 December, if deferrals (including catch-ups) are wanted for this year.
• Deferrals actually made during the year — establishment alone, without deferrals, saves nothing.
• Age checked at year-end: 50+ ($8,000 catch-up) or 60–63 ($11,250 catch-up) for 2026.
• SEP establishment/funding deadline noted: filing deadline with extensions — and the extension actually filed, if relied on.
• Personal IRA deadline noted separately: filing deadline, extensions do not move it.
• Employer contributions (Solo employer part, SEP) calculated on final profit figures before the filing deadline, not estimated in December and forgotten.
• Hiring plans for next year checked against Solo 401(k) owner-only eligibility.
• Every contribution recorded by tax year, with the account and the date, so a February true-up does not double-count a December transfer.

FAQ

It is January and I have no Solo 401(k). Is 2026 retirement saving closed to me? Not entirely. A SEP IRA can still be established and funded for 2026 up to the filing deadline with extensions, and a personal IRA can still be funded for 2026 up to the filing deadline (without extensions). What is closed is a Solo 401(k) deferral for 2026. That three-way split is the reason this guide exists.

It is December and I am 59. Do I get the $11,250 catch-up this year? No — the enlarged catch-up applies at ages 60–63 at year-end. At 59, the 2026 catch-up is $8,000. The $11,250 window opens in the year you turn 60, assuming the law and limits then in force still provide it — verify that year's figures.

Does a SEP IRA really have no catch-up at any age? Correct. A SEP IRA has no catch-up contributions. Age 50+ extra room is a Solo 401(k) (and personal IRA — $1,100 extra, to $8,600 total for 2026) feature, not a SEP feature.

I hired my first employee in June. Can I still make a Solo 401(k) contribution for that year? That depends on the plan's terms, the employee's eligibility dates, and the timing of the change — it is not answerable from this guide alone. Talk to a tax professional promptly, and do not assume the owner-only plan simply continues unchanged.

Where do I go for the year-round calendar behind these deadlines? Guide C4 — it schedules the December true-up that makes these deadlines usable, and the pause-and-heavy-month pattern that keeps contributions flowing in an uneven year.

Related guides

• Retirement hub
• Guide C1 — SEP IRA vs Solo 401(k)
• Guide C4 — Contributing when income is irregular

What to do next

1. Use the December checklist every year.
2. Check the catch-up rules for your age before you contribute.
3. Consult a tax professional before acting on any deadline or contribution.

Sources

• IRS Notice 2025-67, 2026 amounts for retirement plans and IRAs (Solo 401(k) deferral $24,500; catch-up +$8,000 at 50+, +$11,250 at ages 60–63; combined cap $72,000, $80,000 at 50+, $83,250 at 60–63; SEP cap $72,000, minimum compensation $800; IRA $7,500 / $8,600 at 50+; SIMPLE IRA $17,000 — noted for comparison only).
• IRS Publication 560, Retirement Plans for Small Business (Solo 401(k) establishment and contribution timing; SEP rules; catch-up provisions).
• IRS Retirement Plans FAQs Regarding SEPs (no catch-up contributions; funding up to filing deadline with extensions).
• IRS Solo 401(k) guidance (establishment by year-end for deferrals; Form 5500-EZ above $250,000 in plan assets).
• IRS Publication 590-A, Contributions to Individual Retirement Arrangements (IRAs) (IRA contribution deadline: filing deadline, not including extensions).
• SECURE 2.0 Act catch-up provisions (§109: enlarged catch-up at ages 60–63; §601: Roth designation of SEP contributions).
• Guide C1 on this site (SEP effective 20% rate; Solo deferral plus employer maths; SEP employee rule).

Source links: IRS Publication 560 · IRS announcement of Notice 2025-67, 2026 retirement-plan limits · IRS Publication 590-A (IRAs)

Dated assumptions: figures checked 25 Oct 2026; verify current-year limits before acting. Tax year 2026 throughout. Deadline dates are stated for the common sole-proprietor case; entity type and filing status can change deadline mechanics — confirm yours with a tax professional. Worked examples are fictional. Educational only — consult a tax professional before acting on any deadline or contribution for your situation.

Before you act: tax and retirement rules change, and your situation has details a guide cannot see. For any figure you plan to file, claim, or contribute on the basis of this page, consult a tax professional first.

Related guides and tools

• the retirement hub
• SEP IRA vs Solo 401(k): which lets you save more
• how to keep saving for retirement when your income won't sit still

Dated assumptions: draft content as checked 25 October 2026; tax and retirement figures are for tax year 2026 where stated. Verify current-year limits, rates, and deadlines before acting, as the IRS adjusts them annually.