Small-business plan sponsor reviewing employee-hours data, a 401(k) participation checklist, and payroll records

401(k) Long-Term Part-Time Eligibility: A 2026 Census Checklist

November 10, 2026

Overview: Why long-term, part-time eligibility matters in 2026

Plan sponsors reviewing a 401(k) in 2026 should check whether employees who do not meet the ordinary year-of-service route qualify under the long-term, part-time (LTPT) rule for elective deferrals. The rule is based on each employee’s service history, age, the plan document, and applicable transition provisions—not simply on job labels or calendar-year totals. This checklist outlines a careful census review and when to involve the plan administrator or third-party administrator (TPA).

Key IRS eligibility conditions to apply

For plan years beginning after 2024 (beginning with 2025 plan years), the LTPT service route generally requires at least 500 hours of service in each of two consecutive 12-month periods, plus the applicable age-21 condition. Do not count 12-month periods that began before January 1, 2021 when applying this LTPT transition rule. A participant may also satisfy the ordinary year-of-service route sooner; the plan cannot make an employee wait beyond the applicable statutory limit. Which employee is eligible and the plan entry date depend on the written plan and individual service record.

The rule is for the opportunity to elect salary deferrals. It does not by itself establish that an employee receives a matching or other employer contribution; that question depends on separate applicable law and the plan’s terms. See the IRS Employee Plans News explanation of long-term part-time employees in 401(k) plans, IRS Publication 560, and the IRS overview of 401(k) plan qualification requirements.

Important caveats

Plan terms control the operational details, but a plan generally cannot impose eligibility conditions more restrictive than applicable federal limits. Review the current document and have the administrator or TPA confirm applicable entry-date and transition rules.
Eligibility for elective deferrals is not the same as entitlement to matching or other employer contributions. Whether the employer must match deferrals depends on the plan’s written terms and any nondiscrimination testing requirements.
Individual facts matter: counting methods for hours of service, special unpaid leaves, and prior plan years can affect calculations.

2026 Census-Review Checklist (step-by-step)

Use the following sequential checklist when running your 2026 review. Treat this as an operational workflow—document each step and retain supporting records.

1. Prepare your data set

assemble the employee census for the relevant population (all employees covered by the plan), including name, date of birth, hire date, termination date (if any), payroll identifiers, and employment classification;
gather payroll, timekeeping, and plan-service records that let the administrator test each employee’s applicable 12-month periods; do not assume calendar-year totals alone answer the question;
confirm the employer’s definition of an "hour of service" (most plans follow the IRS rules; see plan document or TPA guidance).

2. Identify the two consecutive 12-month periods

Ask the plan administrator or TPA to identify the applicable 12-month service periods for each employee under the document and governing rules. Do not assume the test is automatically two calendar years or that one company-wide period applies to every hire date. Exclude periods beginning before January 1, 2021 for the LTPT transition rule.

3. Count hours consistently

apply a uniform hours-counting methodology across all employees;
apply the IRS and plan-document rules for which periods count as hours of service;
if using payroll hours, reconcile to timekeeping records where available.

4. Apply age and service tests

confirm age 21 attainment dates for employees who meet the hours test;
verify that any plan-specific entry-date rules (for example, entry only after the next plan entry date) are applied according to the plan document.

5. Flag employees who newly qualify

Create a list of employees who appear to satisfy the age and service rules but have not received the applicable opportunity to elect deferrals. Have the plan administrator confirm each eligibility and entry date before implementing changes.

6. Coordinate notice and enrollment

Coordinate with the plan administrator or TPA to provide the required opportunity to make a salary-deferral election and any notices required by the plan and applicable rules. Confirm timing, content, and delivery method, and retain evidence of who was notified and when.

When your review finds a missed eligibility opportunity

If you discover employees who should have been eligible in a prior period but were not offered elective-deferral enrollment, follow these prudent steps:

document the findings and dates involved;
notify the plan administrator, third-party administrator (TPA), recordkeeper, and legal or tax counsel as required by your governance procedures;
work with those parties to determine a reasonable correction under the plan and current IRS guidance; correction methods, including any required corrective contribution or EPCRS program, are fact-specific and can have deadlines; and
communicate clearly and promptly with affected employees about next steps, including any enrollment opportunities and how prior missed deferral windows will be addressed.

Because corrective paths depend on plan terms, the nature of the oversight, and applicable law, sponsors should not act unilaterally without coordinating with the plan’s TPA, recordkeeper, ERISA counsel, or tax advisor. See the IRS 401(k) fix-it guide for employees not offered a deferral election and the EPCRS overview. These are not a substitute for determining the plan-specific correction path.

Data workflow example: from payroll export to participant notice

export two full years of payroll hours by employee ID (including dates);
normalize hours to the plan’s hours-of-service definition;
run a filter to flag employees with >=500 hours in each consecutive period;
cross-check age 21 attainment and plan entry-date rules;
generate a draft participant list and forward to the TPA/recordkeeper for enrollment set-up;
prepare and deliver required notices and retain proof of delivery.

Service alignment: how VastSolutionsGroup.com can fit into the review

VastSolutionsGroup.com describes qualified-plan and retirement-tax planning services, including assistance with retirement-plan design and defined-benefit plan considerations. Those services may be relevant to a sponsor who is reassessing plan eligibility provisions, testing approaches for long-term, part-time workers, or considering plan design changes. The site overview does not establish that VastSolutionsGroup.com is your plan administrator, recordkeeper, or TPA; sponsors should confirm the firm’s scope of engagement and coordinate any work with their plan administrator, TPA, counsel, or tax professional.

Practical tips to reduce future gaps

document a standardized hours-reporting cadence (quarterly or monthly) and review it as part of routine plan governance;
build a checklist into year-end plan oversight procedures—see Qualified Plan Oversight: 8 Questions Business Owners Should Review Before Year-End for related governance items;
ask your recordkeeper to automate alerts for employees approaching 500 hours in a 12-month period;
train payroll staff on the plan’s hours-of-service definition and on retaining documentation of hours and notices.

Sources & Further Reading

Educational Disclaimer

This article is for educational purposes only and does not constitute legal, tax, investment, or individualized retirement-plan advice. Plan terms and individual facts govern; consult your plan document, plan administrator, TPA, ERISA counsel, or tax professional for decisions affecting your plan or participants.

Conclusion and next steps

For 2026, the LTPT review is best treated as an employee-by-employee service-history check: confirm applicable periods, age, plan terms, and entry dates, then offer eligible workers the required opportunity to elect deferrals. If that review raises broader questions about retirement-plan design or tax planning, VastSolutionsGroup.com lists related services; confirm the scope with the firm and coordinate plan administration with your TPA or administrator. Eligibility and corrections depend on plan terms and individual facts.

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401(k)Long-Term Part-Time Employees Plan Sponsor Employee Census Retirement Plans

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