Financial Advisor for Self-Employed: Solo 401(k), SEP IRA, and Tax Planning

Not tax or investment advice — your specific situation matters. Values are verified for 2026 unless noted.

Self-employed individuals — consultants, freelancers, solopreneurs, independent contractors — have access to retirement accounts and tax deductions that W-2 employees can't touch. A freelancer earning $250,000 net can shelter $72,000 from taxes in a single year using a Solo 401(k). A consultant in their 50s earning $400,000 can potentially shelter $200,000+ annually by adding a defined benefit plan.

The problem: these strategies require active coordination — choosing the right account structure, timing contributions around lumpy income, maximizing the QBI deduction without triggering phaseouts, and integrating with a tax return that's already more complex than average. Most W-2 employees don't have this problem. Self-employed individuals do.

An AUM advisor isn't the natural fit here. Much of your retirement wealth is in accounts they don't manage — your Solo 401(k), SEP IRA, or defined benefit plan. Paying 1% on your taxable brokerage account to get advice on accounts the advisor doesn't touch doesn't pencil out. A flat-fee or hourly advisor — paid for planning, not portfolio size — is better aligned with what self-employed people actually need.

The self-employed retirement account landscape in 2026

Three primary vehicles, each with a different profile. The right choice depends on your income, whether you have employees, and whether you want Roth flexibility.

Solo 401(k): the best vehicle for most solopreneurs

If you have no full-time employees other than yourself (and optionally your spouse), the Solo 401(k) is almost always the best retirement account for high-income self-employed individuals. Here's why.

You contribute as both employee and employer. As the employee, you can defer up to $24,500 of earned income in 2026 (plus $8,000 catch-up if you're 50–59 or 64+, or $11,250 super catch-up if you're 60–63¹). As the employer, you can contribute an additional ~20% of your net self-employment income. Combined, you can reach the $72,000 total plan limit much faster than with a SEP IRA.

Roth option available. Unlike SEP IRAs, Solo 401(k) plans with Roth provisions allow you to make Roth deferrals — after-tax contributions that grow and are withdrawn tax-free. This is particularly powerful during lower-income years (startup phase, sabbaticals, years with large deductions) when your marginal rate is temporarily low.

Mega backdoor Roth. If your Solo 401(k) plan documents allow after-tax non-Roth contributions and in-service distributions, you can contribute after-tax money up to the $72,000 total limit and immediately convert it to Roth — the "mega backdoor Roth." This requires a plan that specifically allows it (Fidelity's self-employed 401(k), for example, does not currently support mega backdoor). A flat-fee advisor can help you evaluate which plan provider fits your strategy.

No requirement to cover employees. The moment you hire a full-time W-2 employee (other than your spouse), you must offer them the same plan. That's when the calculus shifts — often toward SEP IRA or SIMPLE IRA, which have different coverage rules.

SEP IRA: simple, but not always optimal

The SEP IRA is the easiest self-employed retirement account to set up — contributions can be made up to the tax-filing deadline (including extensions), and administration is minimal. The limit is 25% of W-2 compensation or, for self-employed, approximately 20% of net self-employment income after the SE tax deduction, capped at $72,000 in 2026.

The tradeoff: no employee deferral component. If your net SE income is $150,000, your maximum SEP IRA contribution is roughly $27,300 — significantly below what a Solo 401(k) would allow. For solo operators with moderate income, the Solo 401(k) almost always wins. For high earners at or near the $360,000 compensation limit (where both plans cap at $72,000), the plans are equivalent on contribution limit, and SEP IRA's simplicity becomes an advantage.

Defined benefit / cash balance plans for high earners

A defined benefit or cash balance plan allows contributions far above the 401(k) and SEP IRA caps — actuarially determined based on your target retirement benefit, which can be as high as $275,000/year under IRC §415(b). In practice, this means a consultant in their mid-50s earning $500,000/year can potentially contribute $200,000+ annually to a qualified plan, sheltering most of their income from current-year taxes.

The tradeoffs: setup and administration are more complex ($2,000–$5,000/year in actuarial fees), you're committed to a contribution schedule even in low-income years, and assets are locked until retirement (no loans). Cash balance plans pair well with Solo 401(k)s — you max the 401(k) first, then sweep additional income into the DB plan. A flat-fee advisor or CPA who works with high-income self-employed clients can model whether the tax savings justify the administrative cost at your income level.

Tax strategies self-employed investors often miss

QBI deduction (§ 199A) — now 23% under OBBBA

The Qualified Business Income deduction allows eligible self-employed individuals to deduct 23% of their qualified business income (QBI) — permanently, under the One Big Beautiful Bill Act (OBBBA, July 2025), which also increased the rate from 20% to 23% starting 2026.³ For a consultant earning $200,000 in QBI, that's a $46,000 above-the-line deduction.

The catch: the deduction phases out for Specified Service Trades or Businesses (SSTBs) — which includes most knowledge workers (consultants, financial advisors, attorneys, physicians, accountants). The phaseout begins at $197,300 of taxable income for single filers and $394,600 for MFJ filers in 2026, and fully eliminates the deduction at $272,300 / $544,600.³

Maximizing retirement contributions reduces QBI and taxable income simultaneously — which can keep you below the phaseout threshold and unlock a larger deduction. This is exactly the kind of multi-variable optimization a flat-fee planner excels at.

Self-employed health insurance deduction

If you're not eligible for employer-sponsored health insurance (including through a spouse's employer), you can deduct 100% of health insurance premiums for yourself, your spouse, and dependents — above the line, reducing AGI. This includes Medicare premiums for self-employed individuals over 65. Many self-employed individuals underutilize this deduction or apply it incorrectly; a tax-aware planner ensures it's claimed properly.

HSA — the triple tax account

If you have a qualifying high-deductible health plan (HDHP), Health Savings Account contributions are deductible, grow tax-free, and can be withdrawn tax-free for medical expenses. In 2026: $4,400 individual / $8,750 family contribution limits.⁴ Self-employed individuals on individual market plans frequently qualify for HDHPs. Investing HSA assets rather than keeping them in cash is a strategy many miss — an HSA invested in index funds for 10–20 years functions as a supplemental retirement account for healthcare costs.

Backdoor Roth IRA

If your income exceeds the Roth IRA contribution phaseout ($150,000–$165,000 single / $236,000–$246,000 MFJ in 2026), you can still fund a Roth IRA via the backdoor method: contribute to a non-deductible traditional IRA ($7,500 limit in 2026¹), then convert to Roth. The complication for self-employed individuals: if you have a SEP IRA or SIMPLE IRA with pre-tax balances, the pro-rata rule applies, potentially making a portion of the conversion taxable. Rolling your SEP IRA into a Solo 401(k) before year-end eliminates this problem — but requires planning ahead.

Why AUM advisors often don't serve self-employed clients well

An AUM advisor earns a percentage of the assets they manage. For a self-employed person, the assets that generate the most value — the retirement accounts, the QBI deduction, the annual Solo 401(k) contribution decision — often aren't assets the advisor manages at all. Your Solo 401(k) is held at Fidelity in a self-directed account. Your SEP IRA contributions are a tax return question you decide with your CPA. The AUM advisor's real value proposition is portfolio management, and that's not your highest-leverage problem.

The conflicts compound at higher income levels. If you're considering rolling your SEP IRA balance into your Solo 401(k) to enable backdoor Roth contributions, your AUM advisor may be reluctant — that IRA balance is what they manage and bill on. A flat-fee advisor has no position on which account holds your assets.

What a flat-fee engagement looks like for self-employed

The initial engagement for a self-employed client typically covers:

1. Business structure review: Are you an S-corp, LLC, or sole proprietor? The structure affects how retirement contributions are calculated and whether S-corp salary optimization makes sense (S-corp owners can optimize W-2 salary to maximize the employer profit-sharing contribution while minimizing SE tax).
2. Retirement account election: Solo 401(k) vs. SEP IRA vs. adding a cash balance plan. Modeled with your specific income, age, and tax situation.
3. QBI deduction analysis: Are you below, near, or above the phaseout? What contribution strategy keeps you in the optimal zone?
4. Backdoor Roth eligibility: Pro-rata analysis, whether to roll existing IRA balances into the 401(k), spousal IRA options.
5. Health insurance and HSA coordination: HDHP eligibility, HSA investment strategy, Medicare transition timing.
6. Tax projection: Estimated quarterly payment planning, year-end contribution deadlines (Solo 401(k) employee deferral must be elected by December 31 of the plan year; employer profit-sharing can be made by the tax-filing deadline including extensions).

Cost table: flat-fee advisory for self-employed

Compare to a 1% AUM advisor managing $1.5M in your taxable accounts: $15,000/year, every year, primarily for portfolio management. If your real questions are about retirement contributions and tax planning, a flat-fee engagement delivers more relevant guidance for a fraction of the cost.