Contractor Retirement Plans USA: SEP, Solo 401(k), and SIMPLE Compared

Ask most contractors when they plan to retire and you get a version of the same answer: when I can’t swing a hammer anymore. That is a hope, not a plan, and it leaves the owner with nothing to show for twenty years of billable work except the tools in the truck. Here is the uncomfortable part: nobody sets up a retirement account for a self-employed contractor. You have to do it yourself — and the tax code rewards you generously when you do.

Contractor retirement plans are one of the largest legal deductions available to a self-employed operator, yet they sit unused on most job sites. Skip them and you hand the IRS money you could have kept. Worse, every year you wait is a year of tax-deferred growth you never get back.

Why contractor retirement plans matter more than you think

A good year is a taxable event. When the jobs stack up and the revenue lands, that profit flows straight onto your personal return and gets taxed at your full rate plus self-employment tax. A retirement plan is the lever that moves a large slice of that profit into a tax-advantaged account before the IRS touches it. Therefore the real question is not whether to save — it is whether you want to pay tax on this money now or decades from now.

Take a solo general contractor who nets $120,000 in 2026. Without a plan, all of it is exposed. With a SEP-IRA, he can move roughly $30,000 into retirement and cut that amount straight off his taxable income — a five-figure tax saving from one decision. That is why strong operators treat the retirement account as a business move, not a personal afterthought.

The three contractor retirement plans worth comparing

For a self-employed contractor, three plans do almost all the work: the SEP-IRA, the Solo 401(k), and the SIMPLE IRA. Each has a different ceiling, a different setup burden, and a different sweet spot. The table below puts the 2026 figures side by side.

Plan	2026 contribution ceiling	Who funds it	Best for
SEP-IRA	Up to 25% of net self-employment income, capped at $72,000	Employer only (you)	Solo operators who want the simplest setup and a big deduction in a strong year
Solo 401(k)	$24,500 employee deferral plus up to 25% as employer, combined cap $72,000 (about $80,000 if you are 50 or older)	You, as both employee and employer	Saving aggressively at moderate income; anyone who wants a Roth option
SIMPLE IRA	$17,000 employee deferral, plus a catch-up once you are 50 or older	Employee deferral plus employer match	Small crews with a few W-2 employees and little appetite for admin

The pattern is clear. A SEP-IRA is the least paperwork and scales with profit, but you only reach the top contributions at high income. A Solo 401(k) lets you save hard even in a middling year because it stacks an employee deferral on top of the employer piece, though it adds a little admin once the balance grows. Meanwhile a SIMPLE IRA lands in the middle and earns its place once you have W-2 employees you also want to cover.

Where the Solo 401(k) pulls ahead

The Solo 401(k) has one feature the others lack: a Roth option. You can make the employee deferral in Roth dollars, paying tax now so the growth comes out tax-free later. For a younger contractor in a lower bracket, that is often the smarter long game. Furthermore it allows the largest contribution at moderate income, which is exactly where most owner-operators actually sit.

These plans only work when there is real, trackable profit to contribute — and that depends on getting paid in full and on time. SendWork sends the invoice the moment a job closes and flags what is still outstanding, so the money that funds your retirement account lands in the account instead of stalling in someone’s I’ll pay you next week.

How to choose your contractor retirement plan

Match the plan to your reality, not to the theoretical maximum. Run this checklist before you open anything:

• Solo, want maximum savings at moderate income: Solo 401(k). The employee deferral lets you contribute more per dollar earned.
• Solo, want the simplest setup: SEP-IRA. Open it at any brokerage and fund it by your tax deadline.
• You have W-2 employees: SIMPLE IRA or a full 401(k). A SEP forces you to contribute the same percentage for every eligible employee, which gets expensive fast.
• You had a big year and need the deduction now: SEP-IRA, because you can still open and fund it after year-end, up to your extended filing deadline.
• You want tax-free growth: Solo 401(k) with the Roth deferral.

One caution: contributions based on self-employment income use your net profit, not gross revenue, and the math runs after your SE-tax deduction. A tax professional or a plan calculator will nail the exact figure — do not eyeball it. The IRS guide to retirement plans for the self-employed lays out the current limits and setup rules for each option.

The operator takeaway

Retirement is the part of the business that finally pays you back for the years you spent paying everyone else first. This year the move is simple: pick one plan, open it before your filing deadline, and fund it with whatever your profit allows. A partial contribution still beats another year of zero. As the numbers firm up, revisit the ceiling and push closer to it. It also pairs directly with the rest of your tax picture — the same profit drives your quarterly estimated taxes, and your choice between an LLC and an S-Corp changes how much you can shelter. None of it works without clean books, so keep your bookkeeping current year-round.

The contractors who retire on their own terms are not the ones who earned the most. Instead they are the ones who moved profit into a plan, consistently, while everyone else waited to feel ready.

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