If your prior-year wages from the plan sponsor were more than $150,000, IRS guidance says your 2026 catch-up contributions generally must be made as Roth contributions when the plan offers Roth catch-up.
2026 change
The wage test that decides whether your catch-up goes Roth
The IRS says that when a plan has a Roth feature and your prior-year wages from the plan sponsor were above $150,000, your catch-up contributions in 2026 generally must be Roth. Notice what the test is not: household income and Taiwan income are not the stated wage test.
Confirm which W-2 wage amount and which employer entity the plan uses — especially if you transferred from another affiliate or worked a partial U.S. year — because that detail decides whether the rule reaches you. The rule changes the tax character of catch-up money; it does not change the limits.
Contribution limits
The 2026 limits keep deferrals and catch-up separate
For 2026, the basic employee elective-deferral limit is $24,500. The standard catch-up is $8,000 for eligible participants age 50 or older — and if you’re turning 60 through 63, the catch-up can be $11,250 where the plan permits it.
Whether TSMC Arizona’s plan offers catch-up and Roth features at all, and how payroll implements them, comes from the current plan materials. That leaves a short list worth checking before contributions start.
Prior-year wages from the plan sponsor above which 2026 catch-up generally must be Roth
2026 basic employee elective-deferral limit
Standard catch-up for eligible participants age 50 or older
Catch-up for participants turning 60 through 63, where the plan permits
IRS 2026 guidance
Payroll checklist
What to verify before your first catch-up contribution
Confirm your date of birth on file, your prior-year TSMC Arizona wages, the contribution sources you’re using now and any contributions you made to another employer plan during the year.
Keep two questions separate: the Roth catch-up rule is a tax rule, and the employer match is a plan formula — so don’t infer the Arizona match from a forum or another employee group. Use this as preparation for the payroll conversation, not as individualized advice; the current TSMC Arizona documents control both.
Frequently asked questions
Questions employees ask next
What is the Roth catch-up wage threshold for 2026?
$150,000 of prior-year wages from the plan sponsor, under current IRS guidance.
What is the 2026 catch-up limit?
$8,000 for most eligible participants age 50 or older — and $11,250 for participants turning 60 through 63, if the plan permits.
Does this rule confirm the TSMC Arizona 401(k) match?
No. Catch-up tax treatment and the employer contribution formula are separate questions — verify the match in the current Arizona documents.
Primary sources
What this guide is based on
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