Defined Benefit Plans for Solo Founders and Consultants

If you are a Bay Area solo consultant, fractional executive, independent SaaS engineer, or one-person agency clearing $300,000 or more in 1099 income, the single largest tax shelter available to you is probably one your CPA has never mentioned: a Defined Benefit plan. A 50-year-old San Jose consultant earning $400,000 in self-employment income can deduct roughly $280,000 per year through a DB plan, compared to about $70,000 through a SEP-IRA. At a combined 50% federal plus California marginal rate, that is more than $100,000 of additional tax savings every year, year after year, until retirement.

Defined Benefit plans are not new. Big law partners, surgeons, and high-earning solo practitioners have used them for decades. What has changed is that plan-administration costs have come down enough that any consistently profitable solo business can run one. If you are leaving a W-2 and going full-time on your own book, or if you have been a consultant for a few years and your SEP-IRA contributions feel like a rounding error against your tax bill, this is the next move.

This guide walks through what a DB plan actually is under IRC Section 401(a), the actuarial math that drives the contribution number, how to combo a DB with a Solo 401(k) to push total deductions toward $400,000, the setup mechanics, and the funding rules you cannot escape. If your income is lumpy, this plan is not for you. If your income is large and reasonably steady, almost nothing on the tax-planning menu beats it. We help founders and consultants set these up regularly at our tax planning practice.

Why This Is in the Playbook

The math is what makes this strategy so unusual. Most tax-advantaged accounts have hard caps that scale slowly: a Solo 401(k) maxes around $70,000 in 2026 ($77,500 with catch-up), a SEP-IRA caps at 25% of compensation up to the same $70,000 ceiling, a backdoor Roth is $7,000, an HSA is $4,300. None of those caps move based on your age, income, or how close you are to retirement.

A Defined Benefit plan works in reverse. Instead of capping the contribution, the IRS caps the future benefit the plan can promise (currently $280,000 per year in retirement income under IRC Section 415(b)), and the actuary calculates whatever contribution today is required to fund that future benefit. Older participants with fewer years until retirement need larger annual contributions to get there. A 55-year-old can typically contribute 2 to 4 times what a 40-year-old can.

Consider a 50-year-old fractional CFO with $400,000 of net self-employment income. With a SEP-IRA, the maximum deduction is roughly $70,000. With a Defined Benefit plan, the actuary will typically calculate an annual required contribution of $260,000 to $290,000. At a combined 37% federal plus 12.3% California marginal rate, the additional $210,000 deduction saves about $103,000 in tax per year.

The strategy compounds. That $103,000 in annual tax savings, invested in the plan itself and growing tax-deferred, can produce a retirement balance well over $4 million by age 65. For a consultant who would otherwise be paying full freight on every dollar above $200K, the DB plan transforms the unit economics of running a solo practice.

What a Defined Benefit Plan Actually Is

A Defined Benefit plan is a qualified retirement plan under IRC Section 401(a) that promises a specific dollar benefit at retirement, typically expressed as a percentage of compensation multiplied by years of service. The contribution required to fund that promise is computed annually by an enrolled actuary using assumptions about investment returns, mortality, and retirement age.

The key distinction: in a Defined Contribution plan (SEP-IRA, Solo 401(k), profit-sharing), you choose how much to put in each year. In a Defined Benefit plan, the actuary tells you how much you must put in to fund the promised benefit. The benefit is the input; the contribution is the output.

The IRS caps the annual retirement benefit a qualified DB plan can promise. For 2026, the §415(b) limit is approximately $280,000 per year of retirement income (indexed annually; verify the current-year figure with your actuary or TPA before relying on it for plan design). To fund a $280,000-per-year lifetime annuity starting at age 65, the actuary calculates the present value of that future stream and divides it by the number of years available to fund it. A participant with 10 years to retirement contributes more per year than one with 25 years to retirement.

DB plans are funded entirely by employer contributions. There are no employee salary deferrals. For a solo consultant operating as a sole proprietor or single-member LLC, the business owner is the employer, so the entire contribution is also the owner's deduction.

The Math: Why Age and Income Drive the Number

The contribution formula has three main inputs:

• Target benefit at retirement. Typically the §415(b) maximum ($280,000) or, if lower, your three-year average compensation. A consultant with $400,000 average comp targets the full $280,000 cap. A consultant with $180,000 average comp is capped at $180,000 (the lesser of comp or §415 limit).
• Years until retirement. Standard plans assume retirement at age 62 or 65. A 55-year-old has 10 years to fund; a 40-year-old has 25 years.
• Assumed investment return. Typically 5% to 6%, set conservatively to maximize the required contribution.

Rough contribution estimates for a consultant targeting the §415(b) maximum benefit:

Age	Years to Age 65	Approx. Annual DB Contribution
40	25	$95,000 to $115,000
45	20	$135,000 to $160,000
50	15	$200,000 to $240,000
55	10	$260,000 to $310,000
60	5	$310,000 to $360,000

These are illustrative; actual numbers depend on plan design, actuarial assumptions, and your earnings history. The pattern holds: every five years of age adds roughly $50,000 to $80,000 of allowable contribution. This is why DB plans are most powerful in your 50s and 60s, and why the strategy gets discussed under the heading "catch-up" for consultants who under-saved in earlier decades.

Combo Plans: Pairing DB with a Solo 401(k)

The §415(b) benefit cap and the §415(c) contribution cap ($70,000 in 2026 for defined contribution plans) are separate. That means a solo consultant can run a Defined Benefit plan and a Solo 401(k) at the same time, with the deductions stacking.

The IRS limits the deduction for combined plans under IRC Section 404. When a DB plan is in place, the employer profit-sharing contribution to the Solo 401(k) is capped at 6% of compensation, but the employee salary deferral ($23,500 in 2026, plus $7,500 catch-up at age 50+, or $11,250 if age 60-63 under SECURE 2.0) is unaffected. So the combo math for a 52-year-old consultant with $500,000 net SE income typically looks like:

• Defined Benefit plan: ~$250,000
• Solo 401(k) employee deferral: $23,500
• Solo 401(k) catch-up: $7,500
• Solo 401(k) employer profit-sharing (6% of comp): ~$15,000
• Combined annual deduction: ~$296,000

A Cash Balance plan, which is a hybrid DB plan with a stated account balance, can substitute for or layer alongside a traditional DB plan for similar effect. Cash Balance plans are slightly more common in multi-owner practices because they make benefit allocations easier to negotiate. For a true solo practice, a classic DB or Cash Balance both work; choice usually comes down to whichever the actuary recommends for your facts.

For a deeper walk-through of the Solo 401(k) side of the combo, see our small business 401(k) guide. The DB plan layers on top.

Setup Mechanics

A DB plan must be adopted by the entity (sole proprietor, single-member LLC, S-corp, partnership) before the end of the tax year for which you want to take the deduction. Under the general qualified-plan rules at IRC Section 401(a) and longstanding IRS guidance, the plan document must be in place by your tax year-end (December 31 for calendar-year filers), though contributions can be funded up through the tax filing deadline including extensions.

The setup checklist:

1. Engage a third-party administrator (TPA) with an enrolled actuary. DB plans require annual actuarial valuations, which only an Enrolled Actuary licensed by the IRS Joint Board can sign. Solo-focused TPAs (Pensionmark, OneDigital Retirement, Emparion, Dedicated DB, and several others) typically charge $2,000 to $4,000 per year for setup and $1,500 to $3,000 annually for ongoing administration.
2. Adopt a plan document. The TPA provides a prototype DB plan document tailored to your facts (sole owner, target benefit, retirement age, vesting schedule). You sign it before year-end.
3. Open a plan trust account. Fidelity, Schwab, and Vanguard all custody DB plan trust assets. The trust is a separate legal entity from your operating business and from your personal IRA.
4. Fund the actuarial contribution. You have until your tax filing deadline (including extensions, so up to October 15 for individuals on extension) to fund the required contribution for the prior tax year.
5. File Form 5500-EZ annually if assets exceed $250,000. The Form 5500-EZ is a short annual return for one-participant plans, due July 31. Under the $250,000 asset threshold, no filing is required until the year the plan terminates.

Form 5305-SEP, used to establish a SEP-IRA, does not apply here. DB plans require a customized actuarial plan document and cannot use the simplified prototype-form route that SEP and SIMPLE plans use. See the IRS Defined Benefit Plan overview for the official summary.

Funding Rules You Cannot Escape

The same actuarial framework that allows huge deductions also imposes a hard funding requirement. Once your plan is adopted, the actuary calculates a minimum required contribution each year, and you must fund it. You cannot skip a year because cash was tight, and you cannot dial the contribution down by half because you decided to take a sabbatical.

If you genuinely cannot fund the required contribution, your options are:

• Amend the plan to reduce the benefit formula prospectively (lowering future required contributions, but not past ones).
• Freeze the plan (stop accruing new benefits; no new contributions required, existing assets continue to grow tax-deferred).
• Terminate the plan (distribute assets to participants, typically rolled to IRAs).

Missing a required contribution without amending or freezing the plan triggers a 10% excise tax under IRC Section 4971 on the funding shortfall, escalating to 100% if not corrected. The IRS treats funding failures as serious; this is not a "we will deal with it next year" situation.

The practical implication: a DB plan suits consultants whose income is predictably high. Fractional executives on multi-year retainers, partners in established practices, consultants with steady book-of-business revenue. If your income swings from $150K one year to $500K the next, a DB plan is risky. A Solo 401(k) with profit-sharing flexes year by year; a DB plan does not.

Worked Example: 52-Year-Old SaaS Consultant

To make the math concrete, consider Anna, a 52-year-old SaaS pricing consultant operating as a single-member LLC, with $500,000 of net self-employment income in 2026. She has been a W-2 employee her whole career until two years ago and has not maximized retirement savings.

Her CPA proposes a combo DB + Solo 401(k) for the 2026 tax year:

Item	Amount
Defined Benefit plan contribution (actuarially calculated)	$255,000
Solo 401(k) employee deferral	$23,500
Solo 401(k) catch-up (age 50+)	$7,500
Solo 401(k) employer profit-sharing (6% of comp)	$15,000
Total combined deduction	$301,000

At a 37% federal marginal rate plus a 9.3% California marginal rate (roughly 43% combined after factoring in deductibility of state tax), Anna's tax savings from the $301,000 deduction is approximately $130,000 for the year. Plan administration costs her $3,500. Net benefit: $126,500 in year one, repeating each year through age 65.

By contrast, if Anna had used only a SEP-IRA, her maximum deduction would have been about $70,000 (the §415(c) limit), saving roughly $30,000 in tax. The DB combo delivers an additional $100,000 per year of tax savings versus the next-best alternative.

What Goes Wrong Without a CPA

The most common mistake we see at intake: a high-earning consultant set up a SEP-IRA early in their solo career, never revisited it as income climbed, and is now over age 45 leaving $50,000 to $120,000 per year of additional pre-tax deduction on the table. The cumulative cost over a decade is routinely $700,000 to $1.5 million in foregone tax savings, plus the missed compounding inside the plan.

DIY tax software flags the $70,000 SEP-IRA cap and stops there. It does not surface DB plan eligibility, it does not model combo plans, and it does not coordinate the §404 deduction interaction between DB and Solo 401(k). Those are the items where engagement with a CPA pays for itself many times over per year.

Exit Strategies and Distribution Rules

A DB plan does not run forever. At retirement, plan termination, or business closure, the accumulated assets must be distributed. The standard exit paths:

• Lump-sum rollover to an IRA. The most common exit. The full plan balance rolls tax-free to a Traditional IRA, where it continues to grow tax-deferred and is taxed only as you take distributions in retirement.
• Annuitization. The plan purchases a lifetime annuity from an insurance carrier that pays the participant the promised monthly benefit. Rare for solo plans; more common in traditional pension contexts.
• Lump-sum distribution to the participant. Taxable as ordinary income in the year received, plus a 10% early-distribution penalty under IRC Section 72(t) if taken before age 59½. Generally avoided except in narrow planning situations.

The §72(t) penalty is the key rule to remember: any DB plan distribution taken before age 59½ that is not rolled over to another qualified plan or IRA incurs a 10% federal penalty on top of ordinary income tax. California adds an additional 2.5% state penalty. Exceptions exist (disability, substantially equal periodic payments under §72(t)(2)(A)(iv), separation from service after age 55 in narrow cases) but for most solo consultants the practical rule is: do not touch the money before 59½.

Plan termination is also an option mid-career. If you wind down your consulting practice, take a W-2 job, or simply want to consolidate retirement assets, you can terminate the DB plan, file a final Form 5500-EZ, and roll the balance to an IRA. There is no penalty for terminating a plan that has been in place for several years, though plans that terminate within a few years of adoption can attract IRS scrutiny on the question of whether the plan was a legitimate retirement vehicle or a one-time tax shelter.

When This Strategy Fits and When It Does Not

A Defined Benefit plan is the right move when several conditions line up:

• You are a solo business owner or partner in a small practice, ideally over age 40, ideally over age 50
• Your net self-employment income is consistently above $250,000, with the largest savings above $400,000
• Your income is reasonably stable, not subject to large year-over-year swings
• You have already maxed out a Solo 401(k) or SEP-IRA and still want to save more pre-tax
• You plan to keep earning at this level for at least 5 years (longer is better)

It is the wrong move when:

• Your income is lumpy (deal-based, equity-based, or feast-or-famine consulting)
• You have employees other than a spouse (every eligible employee triggers required contributions for them too, which usually breaks the economics for solo-focused plans)
• You are under 40 and the actuarial contribution is too small to justify the administration overhead
• You expect to wind down the business within 2 to 3 years
• You need the cash for business reinvestment more than the tax deduction

The employee question deserves emphasis. The moment you hire a W-2 employee (other than a spouse), they generally become eligible for the plan, which means the employer must fund their actuarial benefit too. This either dilutes your own benefit allocation or substantially raises the employer's total contribution. Solo plans are designed for true one-person (or one-person-plus-spouse) operations. If you are running a real agency with staff, the calculus changes completely and you should talk to a TPA before proceeding.

Frequently Asked Questions

Can I have a Defined Benefit plan and a Solo 401(k) at the same time?

Yes. The two plans have separate IRS contribution caps, and combo designs are common. The employer profit-sharing component of the Solo 401(k) is limited to 6% of compensation when a DB plan is in place (under §404 deduction rules), but the employee deferral and catch-up contributions are unaffected. Most solo DB plans we set up at SVT pair with a Solo 401(k) to maximize total deductions.

What happens if my income drops in a future year?

The minimum required contribution is computed based on the plan's funding rules, not on your current-year income. If you cannot fund the required amount, you have three options: amend the plan to reduce the benefit formula going forward, freeze the plan (stop new accruals), or terminate the plan. Skipping a contribution without one of these formal actions triggers a 10% excise tax under §4971. Plan design discussions should include downside scenarios.

Can my spouse also contribute through the plan?

Yes, if your spouse is a legitimate employee of the business. They become a plan participant, accrue their own actuarial benefit based on their compensation and age, and receive their own employer contribution. For a dual-income couple where one spouse runs a consulting practice and the other does meaningful work for the business, this can substantially increase total household pre-tax savings. The spouse's compensation must be reasonable and documented.

How much does it cost to run a DB plan each year?

Expect $2,000 to $4,000 in setup costs (year one) and $1,500 to $3,000 per year in ongoing TPA and actuarial fees. Custodial fees at Fidelity, Schwab, or Vanguard are minimal or zero for solo plans. Form 5500-EZ filing (once assets exceed $250,000) is typically bundled into the TPA's annual fee.

What is the difference between a Defined Benefit plan and a Cash Balance plan?

Both are technically DB plans under IRC §401(a). A traditional DB plan promises a monthly benefit at retirement; a Cash Balance plan promises a hypothetical account balance that grows by a stated contribution credit plus an interest credit each year. The funding math is similar and the deduction is similar. For a solo practice, choice between the two is usually driven by what your TPA prefers; both achieve the same tax outcome.

What if I am a founder running a startup, not a solo consultant?

If your startup has employees, a DB plan generally does not work because you would have to fund actuarial benefits for the whole team, which is expensive and may not match your team's preferences. If you are a true solo founder taking founder distributions through an S-corp or LLC, a DB plan can work, but you should also be looking at QSBS planning, deferred compensation, and other founder-specific strategies. Our startup founder tax practice coordinates retirement planning with equity strategy.

When to Talk to Us

Defined Benefit planning is one of the highest-dollar moves available to high-earning solo consultants in the Bay Area. A 50-something fractional CFO clearing $400K in 1099 income can save more on taxes through one well-designed DB plan than through every other strategy combined. The catch is that the plan must be in place before year-end and the actuarial work takes time to set up properly.

At Silicon Valley Tax, we coordinate DB plan design with TPAs, model the multi-year deduction and contribution path for your specific facts, and integrate the plan with your overall tax strategy (Solo 401(k) layering, S-corp salary optimization, mega backdoor Roth stacking where applicable, and California planning). If you are a consultant, fractional executive, or solo professional with high steady income and no employees, the right time to start this conversation is the third quarter, with a target adoption date of November or December.

Schedule a complimentary consultation and we will run the actuarial estimate for your income, age, and target retirement date, then map out whether a DB plan, a Cash Balance plan, or a Solo 401(k) profit-sharing maximization is the right call for your situation.