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SECURE 1.0 and SECURE 2.0 have quietly reshaped how dental practice 401(k) plans must operate. Rules around long-term part-time employees, Roth catch-up contributions for higher earners, automatic enrollment, and required minimum distributions have already taken effect—or will soon—whether your plan documents have been updated or not.
For dentist-owners, the risk isn’t whether you have a retirement plan, but whether it’s being administered under current law. Part-time employees may now be eligible sooner than expected, high earners age 50+ may be required to make catch-up contributions as Roth, and payroll systems must correctly track multiple contribution types. Safe harbor status does not exempt a practice from these requirements.
The good news: most compliance issues can be corrected if identified early. The bad news: waiting until an IRS or Department of Labor inquiry dramatically raises the cost and complexity of fixing mistakes. A proactive review—aligning plan documents, recordkeeper settings, and payroll processes—is now essential to keeping your 401(k) a strategic asset rather than a regulatory liability.
Read on for the full article…
Picture this: you’re in the middle of a packed clinical day when a letter lands on your desk from the IRS or the Department of Labor. It’s not about income taxes. It’s about your 401(k).
The letter questions why your long-term, part-time hygienist was never allowed into the plan—or why your own age-50+ catch-up contributions are still going in pre-tax when SECURE 2.0 says they should be Roth.
In that moment, it doesn’t matter that you “have a plan.” What matters is whether your plan is operating under today’s rules—or quietly drifting out of compliance.
The SECURE Act of 2019 (SECURE 1.0) and the SECURE 2.0 Act of 2022 changed the rules around eligibility, Roth contributions, catch-ups, auto-enrollment, and required minimum distributions (RMDs) more than anything we’ve seen in years.[1][2] For dental practices with a 401(k), these changes are no longer theoretical—they’re here.
While both laws touch many types of retirement plans and IRAs, this article focuses on how the rules affect dental practices that sponsor a 401(k) (and, in some cases, 403(b) plans in academic or hospital settings).
What SECURE 1.0 Put in Motion
SECURE 1.0 did two big things that matter to dentist-owners.
First, it pushed back the age at which you and your team must start taking required minimum distributions (RMDs). Instead of beginning at age 70½, most individuals now start later—first at 72, then 73 under follow-up rules—with SECURE 2.0 scheduling a future increase to 75 for some individuals.[5] That gives late-career dentists more time to let assets grow before mandatory withdrawals begin. Starting in 2024, Roth accounts in employer plans are no longer subject to lifetime RMDs.[5]
Second, SECURE 1.0 created a new category: long-term, part-time (LTPT) employees. Starting with hours worked in 2021, a 401(k) must track employees who work at least 500 hours per year for three consecutive years. Beginning in 2024, those LTPT employees who meet the plan’s age requirement must be allowed to contribute their own salary deferrals—even if they never reach traditional full-time hours.[1][3]
For a dental office that relies on part-time hygienists, assistants, and administrative support, this is a significant shift. These rules apply whether your 401(k) is a traditional plan or a safe harbor plan. Safe harbor status helps with testing, but it does not exempt you from SECURE’s long-term, part-time eligibility requirements.
There is one piece of good news: the law does not require you to provide employer matching or profit-sharing contributions to LTPT employees who enter the plan solely due to the LTPT rule—if your plan is drafted accordingly. Guidance from providers and technical summaries confirms that employers must permit deferrals but may choose whether to offer employer contributions and whether to include LTPT employees in certain nondiscrimination tests.[3]
What SECURE 2.0 Changed for Long-Term Part-Timers
SECURE 2.0 took the LTPT concept and accelerated it.
Instead of requiring 500 hours per year for three years, starting with plan years that begin in 2025, employees who work at least 500 hours in two consecutive years must be offered deferral eligibility if they meet the age requirement.[2][4] SECURE 2.0 also extends similar LTPT coverage rules to many ERISA-covered 403(b) plans beginning in 2025, affecting dentists in academic or hospital settings.[4]
Think about your team. A hygienist who consistently works two days a week can easily exceed 500 hours in a year. Under the new timing, that employee may need to be offered 401(k) deferrals much sooner than you’d expect.[1][2]
The Department of Labor and retirement advisors have already flagged LTPT coverage as a real compliance risk. If your hours tracking, eligibility dates, or communication with part-time team members are sloppy, you could be responsible for missed deferrals, make-up contributions, and lost earnings.[1][4]
The Roth Catch-Up Shock for Higher-Earning Dentists
Catch-up contributions are the extra amounts you and other age-50+ employees can contribute on top of the regular 401(k) limit. SECURE 2.0 doesn’t eliminate catch-ups—but it does change the tax treatment for higher-earning employees, often including the dentist-owner.
Under Section 603 of SECURE 2.0 and subsequent regulations, if you’re age 50+ and your prior-year wages from the practice exceed $145,000 (indexed for inflation), your catch-up contributions must be Roth, not pre-tax.[4] Originally scheduled to begin in 2024, the IRS granted transition relief through Notice 2023-62 and later guidance, effectively pushing full enforcement into 2026 and beyond. The direction, however, is clear: high-earner catch-ups are moving to Roth.[4]
For a dental practice, this creates a design decision. If your plan allows catch-ups but does not offer a Roth option, you can’t simply continue operating as you always have. To preserve catch-ups for high earners, your plan must be amended to add a Roth feature, and your recordkeeper and payroll systems must be prepared to administer it by the applicable deadlines.[4]
Once a Roth option is in place, it’s not limited to catch-ups. IRS guidance confirms that employees may designate some or all elective deferrals as Roth, and many plans allow participants to split contributions between pre-tax and Roth in any ratio, subject to overall limits.[5]
This is where tight coordination with payroll becomes critical. Your payroll system needs clear, separate deduction codes for pre-tax deferrals, Roth deferrals, and catch-up contributions so amounts are tracked correctly. Reviewing the first few payroll cycles after any change is wise—small coding errors can quickly turn into expensive correction projects.
What about the match? Employer matching contributions can still be made on deferrals, whether pre-tax or Roth. Traditionally, those employer dollars are deposited pre-tax and taxed upon withdrawal. SECURE 2.0 also allows plans, if amended, to permit participants to elect Roth treatment for employer matching and nonelective contributions—taxable now, but potentially tax-free later if distribution rules are met.[5]
On top of that, beginning in 2025, SECURE 2.0 introduces a “super catch-up” for individuals ages 60–63, allowing higher catch-up limits than the standard age-50 amount. For late-career dentists, this opens the door to significantly higher retirement contributions during peak earning years.[5][7]
Automatic Enrollment and RMDs: Don’t Ignore the “Smaller” Changes
SECURE 2.0 also expands automatic enrollment requirements for many new 401(k) and 403(b) plans. Beginning with the 2025 plan year, most plans established after December 29, 2022 must automatically enroll eligible employees at a default contribution rate and automatically increase that rate over time—unless an exemption applies (such as for certain small employers or existing plans).[6]
On the distribution side, SECURE 1.0 and 2.0 together push RMD ages later (from 70½ to 72 to 73, with a future move to 75 for some individuals), and SECURE 2.0 eliminates lifetime RMDs for Roth accounts in employer plans starting in 2024.[5] This makes Roth contributions even more attractive for many dentists as part of a long-term retirement strategy.
Plan Amendments and Communication: “We’ll Get to It Later” Is Not a Strategy
One of the most confusing aspects of SECURE and SECURE 2.0 is timing. You’re required to operate your plan in accordance with the new rules as they become effective, even though you often have until the end of the 2026 plan year to formally sign many of the plan amendments.[8]
In plain language, that means you may already be subject to long-term, part-time rules and updated RMD ages—and soon to Roth catch-up and automatic enrollment rules—even if you haven’t yet signed a comprehensive SECURE 2.0 restatement.
Compliance is a two-step process:
Day-to-day operations must match current law (eligibility, contribution handling, distribution timing).
The written plan document must be updated to reflect those operations, and participants must be informed through updated summaries or notices.
Once changes affecting eligibility, contributions, or distributions are adopted, ERISA generally requires that participants receive updated plan information—typically through an updated Summary Plan Description or a Summary of Material Modifications—within specified timeframes.[8]
If You Think Your Plan Might Not Be Compliant
If this article has your stomach in a knot, you’re not alone—it did mine. The worst move is to ignore that feeling.
Start by pulling together your plan document, recent amendments, payroll reports, and communications from your recordkeeper, payroll provider, or TPA. Then schedule time with your retirement plan advisor, ERISA attorney, or CPA to confirm that your plan document, recordkeeper settings, and payroll deductions are fully aligned.
The IRS maintains formal correction programs—collectively known as the Employee Plans Compliance Resolution System (EPCRS)—that allow you to fix many common 401(k) mistakes while preserving the plan’s tax-qualified status.[8] Errors such as missed eligibility, missed deferrals, and certain contribution mistakes can often be corrected on favorable terms if addressed proactively, rather than discovered during an IRS or DOL audit.[8]
The Bottom Line for Dentist-Owners
You would never ignore a shadow on an X-ray and hope it resolves on its own. Your 401(k) is no different. SECURE 1.0 and SECURE 2.0 have changed the anatomy of your plan, and “we’ve always done it this way” is no longer a safe diagnosis.
Treat this like a focused case review. Pull your key advisors together and ask a direct question: Are we current on long-term part-timers, Roth and catch-up rules, automatic enrollment—and do our documents and payroll actually match what we’re doing day to day?
If the answer is yes, your 401(k) becomes a strategic asset. It helps you attract and retain great people, signals that you run a disciplined business, and supports the retirement you’re building. If the answer is no, the best time to fix it is now—before the IRS or DOL points it out for you.
References
- https://www.bdo.com/insights/tax/new-requirement-to-cover-long-term-part-time-employees-in-401-k-plans-enters-into-effect
- https://www.ascensus.com/industry-regulatory-news/news-articles/improved-coverage-for-long-term-part-time-employees/
- https://www.ascensus.com/resources/news-and-education/plan-sponsor-education/blog/do-i-need-to-provide-a-401-k-match-for-part-time-employees/
- https://www.irs.gov/pub/irs-drop/n-23-62.pdf
https://www.federalregister.gov/documents/2025/09/16/2025-17865/catch-up-contributions - https://www.fidelity.com/learning-center/personal-finance/secure-act-2
- https://www.irs.gov/newsroom/treasury-irs-issue-proposed-regulations-on-new-automatic-enrollment-requirement-for-401k-and-403b-plans
https://www.employeefiduciary.com/blog/secure-act-2-2025-changes - https://www.investopedia.com/important-changes-401k-8743513
https://www.kiplinger.com/taxes/super-catch-up-contribution-for-age-60-63 - https://www.irs.gov/retirement-plans/epcrs-overview
https://www.irs.gov/retirement-plans/correcting-plan-errors
https://www.dol.gov/sites/dolgov/files/ebsa/about-ebsa/our-activities/resource-center/publications/retirement-plan-correction-programs.pdf
