Roth Catch-Up Payroll: Check Wages Before Routing Contributions
A participant's retirement election can remain unchanged while the required payroll treatment changes at the next calendar year. The employee's age may allow catch-up contributions, but a separate prior-year wage test can require those contributions to reach the plan as designated Roth amounts. A payroll flag called high earner is not enough unless someone can explain its year, wage basis and employer scope.
For 2026, the relevant wage threshold is more than $150,000 of the applicable prior-year wages from the employer sponsoring the plan. That is a test of 2025 wages for 2026 contributions. It does not mean that every dollar the employee defers in 2026 must be Roth, or that household income decides the route.
This guide helps U.S. employers implement an administrator-approved instruction for a conventional private-sector, calendar-year 401(k) plan. It covers the wage evidence, contribution-source routing, payroll trial and acceptance record. The plan administrator or qualified retirement adviser determines plan provisions, eligibility, permitted methods and corrections. Other plan types, special applicability rules and individual investment choices need their own review. Primary guidance was checked on November 9, 2026; the examples are fictional and do not represent product testing.
Contents
Three separate facts drive a catch-up instruction
Start with three questions: may this participant make catch-up contributions, which amounts are catch-up contributions, and must those amounts receive Roth treatment? An answer to one does not answer the others. Someone can be old enough for catch-up contributions without being subject to the mandatory Roth rule. Someone can exceed the wage threshold without being old enough to make age-based catch-up contributions.
The IRS catch-up guidance explains that catch-up treatment can arise when elective deferrals exceed the ordinary dollar limit, an applicable plan limit or the actual deferral percentage testing limit. Therefore, a system that considers only one annual dollar counter may not cover the plan's complete determination.
Obtain a dated instruction identifying the participant population, contribution year, plan and approving administrator. It should say which wage measure establishes the Roth requirement and which process identifies the amounts treated as catch-up. Keep a separate unresolved status where facts or authority are missing. A blank field should not silently become an instruction to continue pre-tax withholding.
Payroll's responsibility is to implement that approved instruction faithfully and prove the result. The retirement recordkeeper must preserve the designated source, while the employer retains responsibility for the work its agreements assign to it. A vendor's general statement that it supports SECURE 2.0 does not demonstrate your particular plan configuration.
If your current payroll process cannot carry the approved catch-up status and contribution source reliably, a free SelectSoftware Reviews advisor conversation can help you compare payroll options against those requirements. Have the plan administrator approve the retirement rules separately, then ask shortlisted providers to demonstrate the actual handoff.
2026 is already an operating year
Do not interpret the general 2027 applicability of the final regulations as permission to ignore the statutory Roth catch-up requirement throughout 2026. The final rule states that it did not extend the administrative transition period in Notice 2023-62. The 2025 final regulations generally apply their Roth catch-up provisions to contributions in taxable years beginning after December 31, 2026, with a reasonable, good-faith interpretation standard before their applicable date.
Those are different timing statements. For the conventional private-sector plan discussed here, establish the approved 2026 operating approach now and the changes needed when the final regulations generally apply in 2027. A project schedule that begins all implementation in January 2027 can leave an existing 2026 obligation unanswered.
The final regulations define the wage test using Social Security FICA wages, associated with Form W-2 Box 3. Their applicability discussion expressly recognizes a reasonable, good-faith approach using Medicare FICA wages before the regulations' applicable date. For 2026, obtain the administrator's documented wage-basis instruction rather than declaring that every existing Box 5 implementation is wrong. Conversely, do not copy a transitional approach indefinitely without checking its continuing applicability.
Governmental plans and plans maintained under collective bargaining agreements have special applicability provisions; some multiemployer plans also receive specific treatment. Do not decide their dates from this private-sector example. Ask the authorized plan reviewer to identify the relevant provision, applicable date and interim operating requirements.
For every year, distinguish a legal effective or applicability date from the date a provider installs a setting. Record both. A feature release announcement does not establish that earlier contributions were handled correctly.
The wage file needs a year and an employer
Notice 2025-67 sets the 2025 Roth catch-up wage threshold used for 2026 contributions at $150,000. The comparison is whether the applicable wages exceeded that amount. Exactly $150,000 does not exceed it. A current annual salary of $170,000 does not, by itself, establish what the employee received from the relevant employer in 2025.
Keep the wage year next to the contribution year in the working record. A file named 2026 catch-up may legitimately contain a 2025 wage field, a 2026 status and current 2026 deferral totals. If the importer treats all three as current-year values, a plausible-looking file can produce the wrong instruction.
Identify the wage definition, employer and source record behind the total. Salary, federal taxable wages, Social Security wages, Medicare wages and a plan's eligible compensation are different measures. Use the administrator-approved basis for the applicable year. Reconcile the selected measure to the supporting payroll or reporting record and explain any adjustments, rather than choosing the largest available earnings field.
The final regulations generally identify the sponsoring employer by the participant's common-law employer, with specific optional aggregation provisions for certain related employers or common-paymaster arrangements and special acquisition rules. A shared payroll login, common owner or consolidated report does not decide which wages to combine. Obtain the plan's documented employer-scope instruction before merging wage histories.
A midyear hire illustrates the risk. The employee might have earned substantial wages at an unrelated former employer but little or nothing from the current sponsoring employer in the preceding year. Do not automatically substitute the employee's total wages from every job. At the same time, wages from an acquired or related entity may need a specific determination. Give the administrator the employment and employer history rather than trying to settle the issue by employee name alone.
Preserve a reference to the evidence used, its extraction date and the person who approved the status. A corrected prior-year wage statement should create a review event. It should not overwrite the old status without recording why it changed and which current-year contributions may be affected.
The wage test, age test and current contribution history use different facts. Keep their years and sources visible.
Age controls capacity; wages control the required tax source
For the conventional 401(k) example, the ordinary 2026 elective deferral limit is $24,500. The general age-50 catch-up amount is $8,000. The higher catch-up amount for a participant who turns 60, 61, 62 or 63 during 2026 is $11,250. These 2026 IRS amounts do not eliminate other applicable plan, compensation or testing constraints.
A participant who reaches age 50 by the end of the calendar year can satisfy the age condition, subject to the plan's rules. A participant turning 64 is outside the special 60-through-63 band for that year. Store the approved age category or eligibility result needed by payroll, with an evidence reference. Do not distribute full birth-date files to every person reviewing a contribution export.
Consider two otherwise eligible participants in a plan offering the relevant features. Both had $150,100 of the approved sponsoring-employer wages for 2025. One turns 56 in 2026 and the other turns 62. Both exceed the wage threshold; their potential catch-up capacity differs. Under the stated 2026 dollar amounts, the first has an $8,000 catch-up amount and the second an $11,250 amount.
Now change only the second participant's approved 2025 wage amount to exactly $150,000. The threshold does not require that participant's catch-up contributions to be Roth. This does not prohibit voluntary designated Roth contributions permitted by the plan. It also does not decide which investment or tax choice is best for that employee.
Keep the two decisions in separate fields. Age eligibility and capacity belong in one determination; the mandatory Roth wage test belongs in another. A single highly compensated employee flag can confuse this rule with other retirement-plan testing definitions and thresholds.
For a later contribution year, obtain the IRS amounts for that year and the administrator's approved implementation. Do not carry forward the 2026 figures automatically. The final regulations contain illustrative 2027 assumptions; those example numbers should not be treated as an annual cost-of-living announcement.
Run a paycheck that crosses the ordinary limit
Use a controlled payroll preview to test the exact point at which the approved routing changes. Choose a fictional participant age 56 with $165,000 of the approved 2025 employer wages. The administrator has confirmed the participant's catch-up eligibility and mandatory Roth status for 2026. The plan offers designated Roth contributions and uses the ordinary-dollar-limit crossing in this example.
Before the illustrated paycheck, the participant has $23,900 of 2026 elective deferrals, all pre-tax. The approved deduction for this check is $1,000. There is $600 remaining before the $24,500 ordinary limit: $24,500 minus $23,900. Under these stated assumptions, the check contains $600 of ordinary pre-tax deferral and $400 of Roth catch-up contribution.
After the check, the expected cumulative amounts are $24,500 pre-tax and $400 designated Roth, totaling $24,900. The employee's total retirement deduction for the check remains $1,000. The changed tax treatment can affect taxable wages and net pay, so identical deduction cash does not imply an identical paycheck.
Do not turn that arithmetic into a universal catch-up algorithm. It assumes no earlier designated Roth deferrals, no lower employer or testing limit, sufficient eligible compensation and available pay, and no other contribution history that changes the administrator's instruction. Record those assumptions with the trial. A separate catch-up election design can also require a different processing route.
Check the actual preview fields: participant identity, deduction total, pre-tax amount, designated Roth amount, cumulative totals, tax treatment and retirement export source. Then have the reviewer compare the output with the approved example before the real affected payroll is released. A screenshot of a configuration switch does not prove that the calculation or file uses it.
Test one following check as well. If another approved $1,000 falls entirely into catch-up under the same assumptions and capacity remains, the payroll and export should follow the authorized Roth route. This second check helps reveal settings that split the crossing paycheck correctly but revert to the old source afterward.
This trial assumes no earlier Roth deferrals and an administrator-approved dollar-limit crossing. It is not a substitute for the plan's complete catch-up determination.
Earlier Roth deferrals change the question
An employee may already have made voluntary designated Roth contributions before reaching the ordinary limit. Do not assume those amounts are irrelevant, or assume without approval that every later dollar must automatically switch sources in the same way as the preceding example.
The final regulations' coordination rules address designated Roth contributions made earlier in the year and the plan's implementation of deemed Roth catch-up elections. Ask the administrator which permitted method the plan uses, how earlier Roth contributions are considered and when payroll must treat a subsequent contribution as Roth. Obtain instructions that the payroll system and recordkeeper can both execute.
Keep ordinary pre-tax deferrals, ordinary designated Roth deferrals and amounts treated as catch-up distinguishable in the review evidence, even when the provider's file design uses a combined Roth source. A combined source may be appropriate for the destination, but the reviewer still needs enough detail to reproduce the approved catch-up determination.
A deemed election is also a plan arrangement with conditions, not a payroll operator's general authority to convert contributions. Confirm how the arrangement is documented, how participants receive the required opportunity to make a different election and what payroll does when a participant changes an instruction. Do not replace an unresolved election issue with an unexplained default.
Ask for a second trial containing earlier Roth deferrals. Require the administrator to provide the expected answer before the demonstration. A vendor's ability to reproduce a simple all-pre-tax crossing does not establish that it handles the plan's other permitted methods.
Use these two trials, one without earlier Roth contributions and one with them, when discussing payroll providers with a SelectSoftware Reviews advisor. Compare the payroll and retirement handoff each provider proposes, then verify the plan-specific methods and outputs directly.
A source code must survive both systems
The IRS designated Roth guidance describes separate accounting for designated Roth contributions. A general after-tax deduction is not automatically a designated Roth contribution. Confirm the exact payroll code, tax settings and destination source that represent the approved treatment.
Follow one participant from the reviewed pay register into the transmitted retirement file and the recordkeeper's accepted participant transaction. Compare identity and source as well as amount. If $400 arrives in the traditional source instead of the designated Roth source, matching the total transfer does not resolve the error.
Check tax and reporting settings independently of the export. The 2026 Form W-2 instructions distinguish designated Roth 401(k) contributions reported with Box 12 code AA from pre-tax deferrals reported with code D. Do not invent a new W-2 box code simply because the payroll system has a separate internal catch-up label.
Review the paycheck effect with the payroll tax reviewer. Designated Roth contributions are included in current income; the IRS contribution-withholding guidance distinguishes income-tax treatment while generally including employee pre-tax and designated Roth contributions in Social Security and Medicare wages. Tax calculations still depend on the employee's actual circumstances and applicable limits.
Explain the change to the employee in operational terms: the affected pay date, contribution amount, approved source treatment and contact for election or plan questions. Avoid promising a particular tax saving or future investment result. If available pay cannot support the proposed deduction and taxes, obtain a supported payroll instruction rather than reducing another obligation silently.
Exceptions that defeat a simple high-earner flag
A new provider can receive correct current-year deferral totals while missing the prior-year wage evidence used for the Roth determination. Those are separate histories. Confirm that the changeover preserves both, along with the administrator's status, contribution-source mapping and any earlier Roth amounts relevant to the plan's method.
A transfer between employing entities needs its own check. The final regulations permit specified aggregation approaches in certain related-employer and common-paymaster situations; they do not make every corporate-group payroll total interchangeable. Keep the applicable employers identified in the plan instruction. A transfer or acquisition should trigger review when it changes the facts supporting the determination.
A participant with no relevant prior-year FICA wages also deserves an explicit status rather than an assumed zero caused by an incomplete import. The general wage test and a missing wage record can produce similar-looking system values for different reasons. Ask whether the evidence establishes no applicable wages or merely fails to supply them.
If the plan lacks the required Roth feature, do not create a generic after-tax workaround. Return the affected catch-up instruction to the administrator for a documented decision about plan provisions and available contributions. The final regulations discuss plans without a qualified Roth contribution program and related availability or testing considerations; payroll should not resolve those plan-design questions by changing a deduction label.
Treat a late or corrected wage record as a new determination request. Identify the original wage evidence, revised evidence, approval date and current-year contributions already processed. Separate the prospective payroll setting from any earlier contribution correction. Changing the next paycheck alone does not establish that the historical transactions or reporting are repaired.
When withholding has already taken the wrong route
Preserve the original payroll, election or deemed-election instruction, wage determination, transmitted source and participant transaction. Establish which amounts were affected and whether the money was withheld, sent or credited. A payroll-only reversal may be inappropriate once the recordkeeper holds the amount.
The final regulations provide specific correction methods and conditions, including a Form W-2 method and an in-plan Roth rollover method. The Form W-2 method has a timing restriction tied to whether the form has already been filed or furnished. Do not assume that issuing a W-2c makes every correction method available. Have the administrator and reporting owner select the applicable route under the governing rules and the plan's circumstances.
The final regulations also set correction deadlines, including excess-deferral tax consequences if required correction of an amount above the ordinary annual limit remains incomplete by April 15 following the deferral year. Escalate a misrouted amount when it is found and record the deadline the administrator confirms for the applicable year and method.
An error identified before release has a different operational solution from one found after participant credit or tax reporting. Record the stage, detection date, affected pay dates, amount, source and decision owner. Ask what earnings or losses, tax reporting, employee communication and completion evidence the approved correction requires.
Keep cash reconciliation and source correction separate. The right total can already be in the plan while its tax source is wrong. Conversely, changing a payroll label cannot deliver money that never arrived. Close the exception only after each affected record agrees with the approved correction, or the authorized reviewer documents a remaining item and its next action.
Catch-Up Wage and Routing Review
Use one review for a participant and contribution year, with a separate batch-level summary for the payroll being released. Copy the fields below into a controlled worksheet or notes document. Record restricted evidence references rather than full personal tax returns or unnecessary identity documents.
Determination header
1. Participant and plan: Internal participant reference, employing entity and exact plan: ____________________.
2. Contribution year: Calendar year being processed and first affected pay date: ____________________.
3. Approved age category: Catch-up eligibility and applicable age band, with reviewer and evidence reference: ____________________.
4. Plan authority: Administrator instruction, Roth feature and applicable implementation or transition approach: ____________________.
5. Limit schedule: Current-year ordinary limit, permitted catch-up capacity and any lower plan or testing instruction: ____________________.
Prior-year wage evidence
6. Wage year and basis: Prior calendar year and the approved wage measure for this implementation year: ____________________.
7. Employer scope: Included employer or approved aggregation, with plan instruction reference: ____________________.
8. Wage result: Supported total, applicable threshold and whether the total exceeds it: ____________________.
9. Evidence status: Reconciled source reference and extraction date, or missing/corrected evidence requiring review: ____________________.
10. Authorized routing status: Required Roth, not required by this wage test, or unresolved; approver and effective date: ____________________.
Keep an unresolved determination visibly separate from an approved result. Record its owner and due date before deciding which contribution processing can proceed.
Payroll and destination trial
11. Opening deferrals: Current-year pre-tax and designated Roth totals, including relevant prior-provider history: ____________________.
12. Planned deduction: Authorized amount or rate for the illustrated paycheck and available-pay condition: ____________________.
13. Catch-up method: Administrator-approved crossing, separate-election or other supported treatment, including how earlier Roth amounts are considered: ____________________.
14. Expected split: Ordinary and catch-up amounts, approved tax sources and expected ending totals: ____________________.
15. Observed paycheck: Actual preview amounts, tax treatment, cumulative totals and reviewer evidence: ____________________.
16. Destination result: Export source and recordkeeper acceptance or participant-credit reference for the same amounts: ____________________.
A correct preview establishes the proposed payroll result. Participant credit requires its own later evidence; do not mark it complete before that evidence exists.
Acceptance and follow-up
17. Release decision: Approved processing, restricted processing or unresolved condition; authorized decision maker: ____________________.
18. Exception record: Affected amount, pay dates, source, correction owner and next deadline, if any: ____________________.
19. Employee communication: What changes on which paycheck, the contact for election questions and notice/reference retained: ____________________.
20. Next review event: Annual rollover, corrected wages, employer transfer, provider change or another stated trigger: ____________________.
Use the review to assign an action, not to produce a score. A missing wage basis or unapproved source rule needs an answer from its owner before that part of the instruction is treated as settled.
Annual rollover is a new determination
At year-end, replace the operating-year instruction deliberately. Obtain the next year's verified IRS amounts and plan instructions, establish the correct preceding wage year, refresh age categories and reconcile the relevant history. Preserve the prior review so an earlier paycheck can still be explained after the new flag becomes active.
Include at least four cases in the annual acceptance set: an employee below the wage threshold, one exactly at it, one above it crossing the ordinary limit, and one with earlier designated Roth deferrals. Add an employer transfer, corrected wage record or provider conversion when your population contains those events. The expected answers should come from the approved plan method before payroll testing begins.
Ask the payroll and retirement providers to demonstrate the exception route as well as the ordinary file. Who receives a rejected source code? Who can correct a stale wage status? Who confirms the changed participant transaction? Retain names or responsible teams, expected evidence and the escalation route in the service arrangement.
The useful endpoint is a contribution instruction whose year, wage evidence, age category, tax source and destination result can be reconstructed. Keep unresolved plan decisions with the administrator and verify the implementation each time one of those facts changes.
Bring the unresolved system or service handoffs from your Catch-Up Wage and Routing Review to a SelectSoftware Reviews advisor discussion. Use the payroll shortlist to investigate those requirements, with the retirement administrator separately confirming plan rules and correction responsibilities.
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About the author
Ben Scott writes and maintains payroll decision guides for founders and operators. His work focuses on execution realities and how decisions hold up under growth, complexity, and controls and documentation pressure. He works hands-on in HR and leave-management roles that intersect with payroll-adjacent workflows such as benefits coordination, cutovers, and compliance-driven process controls.
