2026 401(k) limits and compliance deadlines for TPAs.
The figures a TPA uses in testing, payroll validation and annual administration for 2026, and the dated deadlines for a calendar-year 401(k) plan. Every number links to its IRS or DOL source.
The limits that drive testing and processing.
These are the 2026 cost-of-living adjustments published in IRS Notice 2025-67 and summarized on the IRS COLA limits page. Checked against both on October 25, 2026.
| Limit | Code section | 2025 | 2026 | Where a TPA uses it |
|---|---|---|---|---|
| Elective deferrals | 402(g)(1) | $23,500 | $24,500 | Payroll validation, excess deferral refunds |
| Catch-up, age 50 and over | 414(v)(2)(B)(i) | $7,500 | $8,000 | Catch-up eligibility and recharacterization |
| Catch-up, ages 60 to 63 | 414(v)(2)(E) | $11,250 | $11,250 | Replaces the age-50 amount for ages 60 to 63 |
| Annual additions | 415(c)(1)(A) | $70,000 | $72,000 | 415(c) testing, excess annual additions |
| Compensation limit | 401(a)(17) | $350,000 | $360,000 | Allocation and testing compensation caps |
| Highly compensated employee | 414(q)(1)(B) | $160,000 | $160,000 | HCE determination for ADP/ACP testing |
| Key employee (officer) | 416(i)(1)(A)(i) | $230,000 | $235,000 | Top-heavy testing |
| Roth catch-up wage threshold | 414(v)(7)(A) | $145,000 | $150,000 | Who must make catch-ups as Roth |
| Defined benefit limit | 415(b)(1)(A) | $280,000 | $290,000 | Combo and cash balance designs |
| SIMPLE deferrals | 408(p)(2)(E) | $16,500 | $17,000 | SIMPLE 401(k) and IRA plans |
Prior-year figures are from Notice 2025-67's own comparisons where stated, and from Notice 2024-80. Always confirm the figure for the plan year and look-back year your calculation needs.
Mandatory Roth catch-up is now an operations problem.
SECURE 2.0 section 603 requires catch-up contributions to be made as Roth for participants whose prior-year FICA wages from the employer exceeded the indexed threshold, $150,000 for the 2026 determination. For a TPA this means three new checks every payroll cycle: identify affected participants from prior-year Box 3 wages, confirm the plan offers Roth deferrals, and flag pre-tax catch-ups for those participants before they post.
- Collect prior-year FICA wages with the census, not just plan compensation.
- Validate each payroll file for pre-tax catch-ups from affected participants.
- Keep a record of how each correction was made if a pre-tax catch-up slips through.
KinetiPlan's payroll validation workflow shows how rule checks at upload catch problems like this before posting.
The 2026 dates a TPA works to.
For a plan with a December 31 plan year end. Plans with other year ends shift each date by the same offset. Weekend and holiday rules can move a filing date to the next business day.
| Date | What is due | Rule | Source |
|---|---|---|---|
| January 31 | Form 1099-R to participants for 2025 distributions | By January 31 after the distribution year | IRS |
| March 15 | ADP/ACP corrective distributions for 2025 without the 10% excise tax | 2½ months after plan year end (6 months for an EACA plan) | IRS fix-it guide |
| April 1 | First required minimum distribution for participants who reached RMD age in 2025 and are no longer working, unless the plan allows deferral | Required beginning date | IRS |
| April 15 | Refunds of 2025 excess deferrals over the 402(g) limit | April 15 after the deferral year | IRS fix-it guide |
| July 31 | Form 5500 or 5500-SF and Form 8955-SSA for 2025, or Form 5558 to extend | Last day of the 7th month after plan year end | DOL |
| September 30 | Summary annual report to participants, if the 5500 was not extended | 9 months after plan year end | DOL |
| October 15 | Extended Form 5500 and 8955-SSA | 2½-month extension with Form 5558 | DOL |
| Early October to early December | Safe harbor and automatic enrollment notices for 2027 | 30 to 90 days before the plan year starts | IRS |
| December 15 | Summary annual report when the 5500 was extended | 2 months after the extended 5500 deadline | DOL |
| December 31 | Last day to correct 2025 ADP/ACP failures under the plan's own correction rules, and 2026 RMDs for participants past their first RMD year | End of the following plan year | IRS fix-it guide |
A deadline is only useful if someone owns the task behind it.
Each date above depends on earlier work: the March 15 refund needs testing done in February, which needs a clean census in January. A TPA with plans on different year ends is tracking hundreds of these chains at once.
- Work backward from each deadline to the census, testing and review tasks it needs.
- Give every task one owner and a due date ahead of the regulatory date.
- Keep the evidence: the test run, the approval and the filing confirmation.
Model what that work costs your team today with the capacity simulator, or see how an ADP failure becomes a corrective distribution.
Primary sources used on this page.
- IRS Notice 2025-67, 2026 amounts relating to retirement plans and IRAs
- IRS news release IR-2025-111
- IRS COLA increases for dollar limitations
- IRS 401(k) plan fix-it guide
- DOL EBSA Form 5500 series
General information for plan professionals, not legal or tax advice. Plan documents, elections and later IRS or DOL guidance can change how a rule applies to a specific plan.
Common questions
What is the 2026 401(k) elective deferral limit?
$24,500 under IRC 402(g), up from $23,500 in 2025, per IRS Notice 2025-67. Participants aged 50 or older can add an $8,000 catch-up, and participants aged 60 to 63 can use an $11,250 catch-up instead.
What is the 2026 HCE threshold?
$160,000 under IRC 414(q)(1)(B), unchanged from 2025. For 2026 HCE determinations, the look-back year compensation test uses the threshold in effect for that look-back year, so check which year's figure your plan's determination needs.
Who must make Roth catch-up contributions in 2026?
Under SECURE 2.0 section 603, participants whose prior-year FICA wages from the employer exceeded the indexed threshold must make catch-up contributions as Roth. Notice 2025-67 sets that threshold at $150,000. Confirm your plan's operational approach and final regulations with counsel.
When is the deadline for ADP/ACP corrective distributions without the excise tax?
Within 2½ months after the end of the plan year, which is March 15 for a calendar-year plan (6 months for a plan with an eligible automatic contribution arrangement). Corrections made later, up to the end of the following plan year, carry a 10% excise tax on the employer.
When is Form 5500 due for a calendar-year plan?
By the last day of the 7th month after the plan year ends, July 31 for a calendar-year plan. Filing Form 5558 extends the deadline by 2½ months, to October 15.
See how KinetiPlan turns these rules into daily work.
Walk through the pilot build with a plan or two of your own: intake checks, testing, deadlines and filing in one place.