A dental practice owner in their peak earning years can often shelter $200,000 to $400,000 a year in retirement accounts, and most are nowhere close. That is the gap this post is about. Between the Solo 401(k), the Safe Harbor 401(k) with profit sharing, the Cash Balance plan, and the traditional Defined Benefit plan, there is a stack that fits almost every dentist depending on practice size, age, and how many W-2 staff are on payroll.
The right plan is rarely just one plan. It is usually two of them layered together, sized to your practice cash flow and what you want your tax bill to look like in April. Here is what each one actually does in 2026, with the numbers, the trade-offs, and the situations where each one earns its place in the stack.
How 2026 Retirement Contribution Limits Apply to Dental Practices
In 2026, an owner-dentist can stack employee deferrals, employer contributions, and a separate defined benefit allocation into the high six figures of pre-tax savings. The IRS sets three big numbers each year that drive everything else: the 401(k) employee deferral limit ($24,500 in 2026), the total defined contribution limit ($72,000), and a separate defined benefit annual benefit cap of $290,000 that translates into much larger contributions for older owners. A fourth number quietly governs all of it — the annual compensation limit, $360,000 in 2026, which is the most W-2 pay any plan formula can count. Per the IRS 2026 cost-of-living adjustments, the catch-up for those 50 and older is $8,000, and the new SECURE 2.0 super-catch-up for ages 60 through 63 is $11,250.
Translation for a dental owner: a 45-year-old earning $400,000 in W-2 wages from an S-corp practice can move close to $72,000 a year through a Safe Harbor 401(k) with profit sharing alone. Add a Cash Balance plan, and the same dentist can layer another $100,000 to $150,000 on top depending on plan design and actuarial assumptions. That is the lever most general dentists and specialists are not pulling.
Solo 401(k) for Solo Dentists with No W-2 Staff
A Solo 401(k) is the default best plan for a dentist who owns a practice with no W-2 employees other than a spouse, because it offers the highest deferral limits with the lowest administrative cost. You get the full $24,500 employee deferral, plus an employer contribution up to 25% of S-corp wages (or roughly 20% of net self-employment income for sole props), capped at the $72,000 combined limit.
For a solo doc working a 1099 associate gig or running a fully-associate-staffed practice, that combination is a clean fit. Where it breaks down is the second a non-spouse W-2 employee becomes plan-eligible. The Solo 401(k) is only “solo” if your headcount is. A hygienist or front-desk hire on payroll generally moves you into Safe Harbor 401(k) territory once they meet the plan’s eligibility rules — age 21 and 1,000 hours in a year under the standard test, or two consecutive years at 500+ hours under the SECURE 2.0 long-term part-time rule.
A Roth Solo 401(k) sleeve is also worth considering, especially for younger owners who expect higher tax brackets in retirement or who want to diversify between pre-tax and post-tax buckets. Roth deferrals count against the same $24,500 deferral limit, and they count against the $72,000 total cap as well — choosing Roth changes the tax treatment of the dollars, not how many dollars fit in the plan.
What Is a Safe Harbor 401(k) and When Should a Practice Adopt One?
A Safe Harbor 401(k) is the version of the 401(k) that lets the owner max out deferrals without failing IRS nondiscrimination testing. For any practice with W-2 staff, this is the workhorse plan. The trade-off is that the employer has to make a mandatory, immediately vested contribution to all eligible employees, either a 3% non-elective contribution or a matching formula worth up to 4% of pay, per IRS guidance on 401(k) plan qualification requirements.
The math works for most dental practices. A practice with three W-2 staff earning a combined $180,000 in wages pays roughly $5,400 in mandatory Safe Harbor contributions (3% non-elective) to unlock the owner’s full $24,500 deferral, $8,000 catch-up if 50+, and a meaningful profit-sharing slice on top. Profit-sharing on top of Safe Harbor can take the owner to the $72,000 combined limit and uses a “new comparability” formula to skew the allocation toward older, higher-paid participants, which in dental practices is usually the owner. That skew is not automatic — it has to pass annual cross-testing, and a young, well-paid staff can compress how far the formula tilts.
This is also where a coordinated tax and payroll setup matters. The Safe Harbor cost only pencils if your W-2 wage to the owner is set high enough to support the deferral and the profit-sharing percentage, which is part of tax planning for dentists and not something to leave to the payroll provider.
Cash Balance Plans Add Six Figures for Owners 45 and Older
A Cash Balance plan is a defined benefit plan packaged in a way that looks and feels like a 401(k), and for dentists 45 and older it is often the biggest pre-tax savings lever available. Contribution limits inside a Cash Balance plan are age-weighted: the older the owner, the larger the allowable annual contribution. A 50-year-old can typically contribute in the range of $150,000 to $200,000 on top of their 401(k). A 60-year-old can often push toward $300,000. These are planning ranges, not entitlements — the actual number comes from an actuary each year.
The plan promises a fixed “pay credit” plus an “interest credit” to participants each year. For staff, the contribution is usually 5% to 7.5% of compensation. For the owner, it is whatever actuarial math allows under the $290,000 annual benefit limit the IRS set for 2026 — that cap is on the annual retirement benefit the plan can promise, which is what indirectly drives the contribution. Aggregate it with the 401(k) Safe Harbor and a 55-year-old practice owner with three staff can often shelter $250,000 to $350,000 a year pre-tax.
The catch is commitment. Cash Balance plans are expected to be permanent when adopted, which in practice means staying open at least three to five years, and they require an enrolled actuary and higher annual administrative cost (commonly $2,000 to $5,000). They also carry a funding obligation: in a down production year, the practice still owes the required contribution. For an owner with consistent practice profit who is behind on retirement savings, that cost is usually a rounding error — but the funding commitment is the real question to answer before adopting one.
Defined Benefit Plans Still Have a Role for High-Income Specialists
Traditional Defined Benefit plans, the kind that promise a fixed monthly payment in retirement, still make sense for a narrow band of dentists: high-income specialists in their 50s with few or no staff who want to maximize the total dollars going in. Because the formula is based on years of service and projected benefit at retirement, an older owner with a short window to retirement can fund the plan very aggressively in the first few years.
Most modern dental practices choose Cash Balance over traditional DB because the per-participant accounting is simpler and the plan is easier to understand for staff. Where traditional DB still wins is when the owner wants every dollar going to themselves, accepts the higher actuarial complexity, and is closing in on retirement fast enough to justify front-loaded contributions.
How to Stack Plans: 401(k) + Cash Balance for Maximum Shelter
The most common high-savings setup for a profitable dental practice is a Safe Harbor 401(k) with profit sharing paired with a Cash Balance plan, because together they can push annual pre-tax contributions into the $250,000 to $400,000 range for owners in their late 40s through 50s. For an associate-staffed practice with no traditional W-2 employees, a Solo 401(k) paired with a Cash Balance plan does the same job with less overhead.
A simple decision tree: If you have no plan-eligible W-2 staff other than a spouse, run Solo 401(k) plus Cash Balance. If you have W-2 staff, run Safe Harbor 401(k) with new-comparability profit sharing plus Cash Balance. The Cash Balance layer is the one most dentists skip, and for an owner with the profit to fund it, skipping it can be the difference between sheltering $72,000 a year and sheltering $250,000 a year.
Plan stacking is also where coordination breaks down between separate advisors. The CPA wants to maximize the tax deduction. The financial advisor wants to manage the assets. The third-party administrator runs the plan. Without one team holding the whole picture, the stack tends to default to the cheapest plan, which is rarely the right one. That is part of the case for integrated retirement planning for dentists.
What These Plans Cost a Practice Each Year
Annual administrative cost for these plans ranges from under $500 for a Solo 401(k) to roughly $4,000 to $6,000 for a stacked Safe Harbor 401(k) plus Cash Balance setup. For an owner funding at these levels, the cost is typically recovered many times over in the first year of contributions. At a 40% combined federal and state marginal rate, $150,000 of Cash Balance contributions can defer roughly $60,000 of current-year tax (2026 example, approximate — this is tax deferred, not eliminated; the money is taxed when distributed). Set against a $5,000 administrative cost, the arithmetic is not close.
The real cost most dentists do not budget for is the time spent on staff communication and onboarding, especially around eligibility and the Safe Harbor match. A good plan administrator handles most of that, but the owner-dentist still needs to sign off on plan design, eligibility tiers, and annual census filings.
Related reading: Health Savings Accounts For Dentists: The Triple-Tax Advantage And How To Use It · Roth Conversion Strategies for Dentists Nearing Retirement
Common Questions
Can I have a Solo 401(k) and a SEP IRA at the same time?
Technically yes, but for the same practice the combined contributions count against the same $72,000 limit, and most dentists who already have a SEP are better off moving to a Solo 401(k) because the 401(k) allows employee deferrals on top of the employer contribution, plus a Roth sleeve and a coordinated Cash Balance layer.
What happens to my plan if I sell the practice?
Cash Balance and 401(k) balances can generally be rolled to an IRA or to the buyer’s plan without current tax. The plan itself is usually terminated at sale, with a final actuarial valuation — and on termination, all participants become fully vested, which is a cost worth modeling before the sale year. Selling is also when the owner often wants to accelerate Cash Balance contributions in the final 1 to 3 years of ownership.
How is a Cash Balance plan different from a 401(k)?
A 401(k) is defined contribution: the contribution is fixed, the benefit depends on investment performance. A Cash Balance plan is defined benefit: the benefit is fixed by formula, and the plan sponsor (the practice) is on the hook to fund whatever it takes to deliver it. That difference is why Cash Balance limits are age-weighted and why the plan needs an actuary.
Do I have to include associate dentists in the plan?
W-2 associates yes, properly classified 1099 associates no. Eligibility rules generally require including any W-2 employee who works 1,000 hours in a year and is age 21 or older, and SECURE 2.0 also brings in long-term part-time employees with two consecutive years of 500+ hours for deferral purposes. Plan design can delay entry, and it is worth stress-testing associate classification before relying on it — a misclassified 1099 associate is both a payroll issue and a plan-qualification issue.
Can I roll my Cash Balance plan into a Roth IRA?
On termination or retirement, the Cash Balance balance can be rolled to a traditional IRA, then converted to a Roth in stages. The conversion is a taxable event, so most dentists stage it across years when income is lower, often during the wind-down years after a practice sale.
If you liked this one, you’ll probably also like our breakdown of reasonable compensation for dentists and how the owner-pay decision drives every retirement number above.
Curious which stack fits your practice? The team at Core Advisors handles tax planning, plan design, and investment management for dentists under one roof, so the 401(k), the Cash Balance plan, and the personal financial picture all line up. Schedule a conversation and we will walk through it.
Until next time!
About the Author
Thomas Gore, CFP®, CPA is the founder of Core Advisors, where he leads integrated tax, accounting, and wealth management services for dental practice owners across the country. He works with dentists on plan design, S-corp tax strategy, and long-term retirement planning that accounts for the practice as the largest asset on the balance sheet.
Educational content only. Not investment, tax, or legal advice. Retirement plan limits and rules change periodically; verify current figures with the IRS or a qualified advisor before acting. Past performance does not guarantee future results.
