For the right business owner, a defined benefit plan can create one of the largest retirement-plan deductions available. This is especially true for profitable business owners in their 50s and 60s who earn a high income and have the cash flow to put away significantly more than the normal 401(k) limits allow.
But defined benefit plans also come with more rules, more costs, and more planning than a traditional 401(k). Here's what matters in 2026.
A defined benefit plan is an employer-sponsored retirement plan that promises a specific retirement benefit.
Instead of simply deciding how much you want to contribute each year, an actuary works backward from that future benefit and calculates how much needs to go into the plan today. And your age is one of the biggest factors.
Someone who is 57 has far fewer years to fund a retirement benefit than someone who is 42. That shorter window can allow an older, high-earning business owner to make a much larger deductible contribution.
That's why these plans tend to work particularly well for:
The ideal candidate usually has consistently high income and enough cash flow to comfortably put a significant amount into retirement each year.
A cash balance plan is a type of defined benefit plan.The biggest difference is how the benefit is presented. Instead of showing a future monthly pension payment, a cash balance plan shows the participant a hypothetical account balance.
That tends to make it easier for business owners to understand, which is one reason cash balance plans are commonly used in small-business retirement planning.
For 2026:
One important distinction:
The $290,000 limit is not a $290,000 contribution limit.
It limits the annual retirement benefit the plan can provide. The amount that can actually be contributed is calculated by an actuary. Depending on the owner's age, compensation, plan design, existing assets, and other factors, the required or permissible contribution can be considerably different—and in some cases can exceed $290,000.
The SECURE Act changed an important deadline.
An employer can generally adopt a qualified retirement plan by the due date of its tax return, including extensions, and elect to treat the plan as having been adopted on the last day of the prior tax year.
That doesn't mean waiting until the deadline is a good idea.
A defined benefit plan involves actuarial design, plan documents, funding decisions, and coordination among several professionals.
If you're considering one for a client, start the conversation well before the tax return is due.
For a calendar-year plan, the final minimum required contribution is generally due 8½ months after the end of the plan year, or September 15.
There's also a separate SECURE 2.0 rule for certain first-year solo 401(k)s. A sole proprietor with no employees may be able to establish a new 401(k) after year-end and make first-year elective deferrals by the individual's tax-return filing deadline, without extensions.
Those are two different rules, so don't confuse the 401(k) deferral deadline with the broader plan-adoption deadline.
Having a profitable business doesn't automatically make a defined benefit plan a good fit. The participant needs compensation or earned income from the business sponsoring the plan. Simply owning a business without performing compensated services isn't enough.
Beyond that, look for a few characteristics.
The business should have relatively consistent profits. You're making a longer-term retirement commitment, so designing a plan around one unusually profitable year can create problems later.
The owner also needs strong cash flow. Unlike a discretionary retirement contribution that can simply be skipped when business is slow, a defined benefit plan can create required funding obligations.
This is where things get more complicated. A business sponsoring a SIMPLE IRA generally cannot also maintain another qualified plan for employees during the same calendar year, except in limited circumstances.
SEPs require a closer look.
If the employer uses the IRS's model Form 5305-SEP, the employer generally cannot maintain another qualified retirement plan. Other SEP arrangements may allow different combinations, so the plan documents need to be reviewed.
Family members can participate too, but they need to be legitimate employees performing real work and receiving reasonable compensation. You don't put a spouse on payroll simply to manufacture another retirement deduction.
This is usually the main attraction. Employer contributions to a qualified defined benefit plan may be deductible, subject to the applicable funding and deduction rules.
For a pass-through business, that can ultimately reduce income flowing through to the owner. The exact tax result depends on the entity structure and the owner's circumstances.
Money inside the plan generally grows without current income taxation. But notice the word deferred.
It isn't automatically tax-free forever. Taxable distributions from a traditional qualified plan are generally taxed as ordinary income.
A defined contribution plan has a $72,000 annual-additions limit in 2026, before permitted catch-up contributions. A defined benefit plan operates under a completely different set of limits.
For the right older, highly compensated owner, combining the two can create substantially more retirement-saving capacity.
This gets interesting. The Section 199A qualified business income deduction is now permanent under OBBBA.
For 2026, the threshold amounts are:
For specified service trades or businesses such as medicine, law, accounting, consulting, and financial services, the deduction can be limited and eventually eliminated as taxable income moves through the applicable phase-in range.
A deductible retirement contribution may reduce taxable income enough to affect that calculation. That doesn't mean a $100,000 retirement contribution automatically creates a specific additional §199A deduction. The retirement contribution can also affect QBI itself, and the interaction needs to be modeled.
Not necessarily. PBGC protection does not apply to every defined benefit plan. For example, plans maintained exclusively for substantial owners can be exempt from PBGC coverage. Certain plans sponsored by professional-service employers that have never had more than 25 active participants can also be exempt.
That's especially important in the small-business plans accountants commonly encounter. Never assume PBGC protection applies without checking the actual plan.
It grows tax-deferred.That's an important distinction. Traditional qualified-plan distributions are generally taxable as ordinary income when the money comes out.
The promised benefit isn't simply reduced because the investments have a bad year. But investment performance still matters to the employer funding the plan. If the plan's assets underperform the actuarial assumptions, future funding requirements can increase.
For an owner-only business, the owner is ultimately on both sides of that equation: they're the participant receiving the benefit and the employer responsible for funding the plan. That's why investment strategy and actuarial assumptions need to work together.
This is one of the easiest places to make an expensive mistake. IRC §404(a)(7) contains special deduction rules when the same employer has both a defined benefit plan and a defined contribution plan covering some of the same participants.
These rules are particularly relevant when the defined benefit plan is exempt from PBGC coverage. There is, however, an important 6% rule.
If employer contributions to the defined contribution plan, excluding elective deferrals, do not exceed 6% of applicable compensation, the §404(a)(7) combined deduction limitation doesn't apply on that basis.
Employee elective deferrals don't count toward that 6%. And if employer contributions exceed 6%, only the employer contributions above 6% are taken into account for purposes of the combined limit.
That's an important correction because this rule is sometimes explained as though crossing 6% suddenly makes the entire defined contribution amount count against the combined limit.
It doesn't. The takeaway is simpler:
Run the combined-plan deduction calculation before the client funds the plans. Don't discover the problem after the money has already moved.
You can't reliably estimate a defined benefit contribution from an article. The actual number depends on age, compensation, plan design, existing plan assets, actuarial assumptions, and other factors. But you can identify the people worth having the conversation with.
An owner in their 50s or early 60s earning $300,000+ with no employees is a strong profile to evaluate. They have high earned income, a shorter retirement funding period, and no rank-and-file workforce adding significant plan costs. A solo 401(k) may also be incorporated into the design.
Two spouses who both legitimately work in the business can both participate. Each participant has their own benefit calculation, based on factors such as compensation, age, and plan provisions. The 2026 compensation limit of $360,000 also needs to be considered when determining benefits.
A physician, professor, executive, consultant, speaker, or other professional with legitimate self-employment income may be able to sponsor a retirement plan through that separate business. Two cautions. The employer plan and the side business plan are tested separately unless a controlled group or affiliated service group exists, which needs checking.
Don’t multiply the entire deduction by the client’s top tax bracket. Suppose a client has $150,000 of taxable income before a $135,000 deductible retirement-plan contribution, assuming the plan design and the client’s compensation support that contribution.
The deduction does not save 24% on the full $135,000.
In 2026, for a single filer:
Total federal income tax reduction: about $27,046, before considering other tax interactions.
That’s an effective savings rate of about 20% on the deduction—not 24%. The actual result can differ once you account for §199A, state taxes, deductions, credits, and the retirement plan’s own compensation and deduction limit
Age matters here too. SECURE 2.0 changed the required minimum distribution ages. Someone born between 1951 and 1959 generally starts RMDs at 73. Someone born in 1960 or later generally starts at 75. So don't build a retirement strategy around "avoiding an RMD" for someone who isn't required to take one yet. There is another planning opportunity to consider.
For 2025 through 2028, taxpayers age 65 and older may qualify for the new $6,000 senior deduction, or up to $12,000 for a married couple if both spouses qualify.
The deduction starts phasing out when modified AGI exceeds:
A retirement-plan contribution that reduces MAGI may therefore affect how much of that deduction the taxpayer can claim. Again, model it rather than assuming a particular result.
Defined benefit plans can produce impressive deductions, but they aren't a "put money in this year and forget about it" strategy.
You're making a longer-term commitment. There isn't a simple statutory rule saying every plan must remain open for exactly three or five years. But qualified plans are supposed to be established with an intention of permanence. Setting one up for a big deduction and quickly terminating it without a legitimate business reason can create qualification issues.
Funding isn't completely optional. Defined benefit plans can have minimum required contributions. Failure to fund properly can lead to excise taxes and additional reporting.
Investment performance affects funding. When plan assets perform differently from actuarial assumptions, required future contributions can change.
Employees can change the economics. Once rank-and-file employees are involved, coverage and nondiscrimination rules may require the employer to make meaningful contributions for them too.
There are real administrative costs. These plans generally require actuarial work, plan documents, annual filings, and third-party administration.
Several professionals may be involved. The CPA, actuary, TPA, and investment advisor may all have a role.
Someone needs to make sure the pieces actually get implemented.
The goal isn't to become an actuary but to recognize when a client's situation is worth exploring. Start by looking through your existing client base.
Which business owners:
From there, an actuary can determine whether a defined benefit or cash balance plan makes sense and calculate the actual funding range.
TaxPlanIQ can help with the tax-planning side of the process by identifying potential strategies, modeling them alongside other planning opportunities, and creating a client-facing plan and proposal.
The platform matches clients against a library of more than 130 tax strategies and helps firms quantify potential savings and present a value-based fee upfront. The actuarial design and administration still belong with the appropriate retirement-plan professionals.
Pull your client list. Flag profitable business owners over 50 with high earned income, strong cash flow, and few or no employees.
Then look at their current retirement contributions, taxable income, §199A position, and longer-term retirement goals. You don't need to know yet whether the right contribution is $75,000, $150,000, or $300,000. You just need to recognize the client who should be asking the question.