Your Q4 Fiduciary Calendar: What To Handle Before the Plan Year Turns Over

Oct 20, 2026

The last quarter of the year fills up fast. Budgets, holiday schedules, year-end close. For small and midsize business owners who sponsor a 401(k), it is also the stretch when several retirement plan deadlines land close together, and when a missed notice or an outdated bond amount can quietly start problems for the year ahead.

In its guide for employers, the Department of Labor describes offering a retirement plan as “one of the most challenging, yet rewarding, decisions an employer can make.” The rewarding part is easy to see. The challenging part often comes down to doing the right things on time, and doing them correctly. Here is a month-by-month look at what calendar-year plan sponsors should have on their radar between now and December 31. (If your plan year runs on a different schedule, the dates shift, so check with your TPA.)

October: Close Out Last Year, Get Ready for Next

Form 5500 on extension? October 15 is the finish line, and your signature is on it. If your plan filed Form 5558 to extend its 2025 Form 5500, the extended deadline for calendar-year plans is October 15, 2026, and there is no second extension. Your TPA may prepare and even submit the form, but the person signing as plan administrator (generally the business owner) declares under penalty of perjury that they have examined it and that it is true, correct and complete. As attorneys at Haynes Boone remind plan sponsors, they “are ultimately responsible for the forms’ correctness.” So read the draft before you sign. Check participant counts, plan assets, and the line asking whether the plan carries an ERISA fidelity bond and for how much, since a bonding gap shows up right there for regulators to see. (More in Form 5500: Is Yours Accurate? and July Is Form 5500 Time: Don’t Let an ERISA Bonding Gap Trigger a DOL Audit.)

The annual notice window is open. Safe harbor 401(k) plans that use a matching contribution owe eligible employees an annual notice before the new plan year starts. According to the IRS, the timing is satisfied when the notice goes out “at least 30 days (and not more than 90 days)” before the plan year begins. For a plan year starting January 1, 2027, that window runs from October 3 through December 2, 2026. Plans with automatic enrollment or a qualified default investment alternative (QDIA) have their own pre-plan-year notices, and many recordkeepers combine them into a single mailing. Safe harbor plans that rely only on nonelective contributions are no longer required to send the safe harbor notice, though some sponsors still do. That exemption does not extend to automatic enrollment or QDIA notices, which still need to go out on schedule.

Your move: Ask your provider for the date the notices will go out and who is responsible for sending them. “Our provider handles it” is not an answer until you have done your oversight job.

November: Check the Numbers Behind the Plan

Is your ERISA fidelity bond still big enough? Under DOL Field Assistance Bulletin 2008-04, each person who handles plan funds must be bonded for at least 10% of the funds they handle, with a $1,000 minimum. For most plans the maximum required is $500,000 per plan, or $1 million if the plan holds employer securities. The amount is set at the start of each plan year based on the prior year’s figures. That means if your plan grew in 2026, a bond that was adequate last January may come up short when 2027 begins. A quick look now is far easier than explaining a gap on next year’s Form 5500. (All About ERISA Bonds: What Every Plan Sponsor Should Know covers the basics.)

Take a year-end look at fees. If your recordkeeper or advisor changed fees this year, write down how you evaluated the change and what you decided. Fee decisions are a frequent target in ERISA litigation, and “we looked at it” carries much more weight when there is a record. Our 401(k) Fee Increase? Here’s Your Plan Sponsor To-Do List walks through the steps.

Spot-check deposit timing. Making timely contributions is one of the core obligations the DOL emphasizes for plan sponsors. Pull a few payroll dates from across the year and compare them to when deferrals actually reached the plan. Late deposits are much simpler to fix when you catch them yourself. (Timely Remittance: A Few Days Late, A Lot at Stake)

December: Lock It In Before Year-End

Plan amendments are due December 31, 2026. For most non-governmental 401(k) plans, this is the deadline to formally adopt amendments reflecting the SECURE Act, SECURE 2.0 and the CARES Act. (You may have seen headlines about an extension to December 31, 2027. That extension covers IRAs, SEPs and SIMPLE IRA plans, not 401(k) plans.) Many plans have been operating under these rules for a while; now the paperwork has to catch up. As attorneys at Baker Donelson note, “any gap between operations and written terms should be identified and corrected promptly.” Ask your document provider for the signed amendment and keep a copy with your plan records. (See Plan Amendments In The Home Stretch of 2026.)

Summary Annual Report. If your Form 5500 was filed on extension, the Summary Annual Report (SAR) is generally due to participants two months after the extended filing deadline. For calendar-year plans, that is December 15. (Plan Sponsors: Why Care About The SAR?)

Document your year. Gather meeting notes, investment reviews, fee comparisons and any decisions about service providers from 2026, and file them in one place. Under ERISA, prudence is judged by the process you followed, and a process nobody recorded is hard to prove later. (ERISA Plans: Making Decisions and Monitoring Results)

Good To Know

Handing off tasks doesn’t hand off accountability. Your TPA, recordkeeper and advisor do much of the work on your plan throughout the year. Choosing them carefully and keeping an eye on their work is still your job as the plan sponsor, and that duty stays with you all year.

The bond protects the plan, not you. An ERISA fidelity bond covers the plan against theft or fraud by people who handle plan money. If a missed notice or an outdated document leads to a participant complaint or a DOL inquiry, the bond does not pay your legal defense. That is what fiduciary liability insurance is for.

Put the dates in your own calendar. Your providers have their own deadlines to juggle. October 15, December 2, December 15 and December 31 belong to you too.

Start the New Plan Year Covered

Year-end is the right time to make sure your protection keeps pace with your plan. Colonial Surety Company makes it simple and affordable for retirement plan sponsors to bundle three essential coverages into one ERISA package:

ERISA Fidelity Bond: meets your federal bonding requirement and protects plan assets from fraud and dishonesty.
Fiduciary Liability Insurance: helps protect you personally, including defense costs, if you are accused of a fiduciary breach.
Cyber Liability Coverage: helps you respond if a cyber incident puts the plan at risk.

Colonial Surety Company is a Treasury Listed surety. Review your ERISA bond and bundle protection options before the new plan year begins.

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