Roth 401(k) Rules

A Roth 401(k) is the employer-plan version of a Roth IRA — post-tax contributions, tax-free growth, tax-free qualified withdrawals. The 2026 contribution limit is $24,500 (no income limit), and employer matching is permitted. SECURE 2.0 §325 eliminated Roth 401(k) lifetime RMDs starting 2024, and SECURE 2.0 §603 (final regs in TD 10007) requires high earners to make all catch-up contributions Roth starting 2026.

2026 Roth 401(k) Contribution Limits

2026: $24,500 for participants under age 50. An additional $8,000 catch-up is permitted for those 50+, for a total of $32,500.

Critical note: The Roth 401(k) limit and traditional 401(k) limit are combined under the same $24,500 umbrella. If you contribute $15,000 to a Roth 401(k), you can only contribute $9,500 to a traditional 401(k) (total: $24,500). Many employees don't realize this and think they can contribute the full limit to each type.

Employer match: Employer contributions are not subject to the annual limit—they are in addition to the $24,500. However, employer match is almost always deposited to the pre-tax (traditional) side of the 401(k) regardless of where you direct your own contributions. This creates a mixed account with both pre-tax and post-tax money.

No Income Limits (Unlike Roth IRA)

This is one of the biggest advantages of Roth 401(k)s. Roth IRAs have income phase-outs—in 2026, single filers can't contribute if their income exceeds ~$168,000, and married filing jointly can't contribute above ~$252,000.

Roth 401(k)s have no income limits. A neurosurgeon earning $750,000/year can max out a Roth 401(k) at $24,500. A hedge fund manager earning $5 million can contribute the same. For high earners who are locked out of Roth IRA contributions, the Roth 401(k) is the primary vehicle for accumulating post-tax retirement savings.

How Employer Match Complicates the Roth 401(k)

When you contribute to a Roth 401(k), the employer match goes to a traditional (pre-tax) account. This means your Roth 401(k) balance has two "buckets": Roth contributions (yours) and pre-tax match (employer's).

Why this matters: When you take withdrawals or roll the account, the Roth and pre-tax portions must be separated. You can't roll the Roth portion and leave the pre-tax portion—they follow different rules.

Example: You contribute $20,000 to Roth 401(k) and earn $5,000 in gains. Your employer matches $6,000. When you roll this account to another custodian, the $25,000 Roth portion (your contributions + gains) goes to the destination, but the $6,000 match must go to a traditional IRA or pre-tax account. You cannot mix them.

Roth 401(k) Withdrawal Rules and the 5-Year Rule

To withdraw from a Roth 401(k) tax-free and penalty-free, you must (1) be age 59½ or older (or qualify for an exception), AND (2) have separated from service, AND (3) have held the Roth 401(k) for at least 5 years.

The 5-year rule: Unlike Roth IRAs, where contributions are always accessible without penalties, Roth 401(k) contributions are locked behind the separation-from-service requirement. You cannot access your Roth 401(k) contributions (or earnings) before age 59½ without penalty unless you separate from service and meet the 5-year rule, or qualify for a hardship withdrawal (which usually requires employer approval and is taxable).

The 5-year clock starts January 1 of the tax year you made your first Roth 401(k) contribution. If you opened a Roth 401(k) in 2024, the 5-year clock started January 1, 2024, and ends January 1, 2029. Contributions made in 2028 are covered by the same 5-year clock.

Critical limitation: Roth 401(k)s do not allow loans (most traditional 401(k)s do). Since you can't borrow from the account and contributions aren't easily accessible before 59½, Roth 401(k)s are less "flexible" than Roth IRAs for emergency access.

SECURE 2.0 §325: Roth 401(k) Lifetime RMDs Eliminated

The SECURE Act 2.0 (December 29, 2022) made two changes that matter here:

Historical Rule (pre-2024): RMDs Required

Through tax year 2023, designated Roth 401(k) accounts were subject to Required Minimum Distributions starting at age 72 (or 70½ for owners reaching that age before 2020). Even though distributions were tax-free, the account holder was forced to take them and deplete the balance. This was a well-known anomaly relative to Roth IRAs, which have never required RMDs for the account owner.

SECURE 2.0 §325: Complete Elimination Effective 2024

SECURE 2.0 §325 eliminated lifetime RMDs on designated Roth 401(k) accounts entirely, effective for tax years beginning after December 31, 2023. This applies to all designated Roth account balances regardless of size — there is no $5 million threshold (a common myth online; the $5M figure appears in unrelated regulatory proposals and is not part of §325).

What this means in practice: An account owner with a designated Roth 401(k) no longer needs to take any RMD during their lifetime from that account. SECURE 2.0 §107 moved the RMD start date on pre-tax balances to 73 (born 1951–1959) or 75 (born 1960+), but that rule does not reach the designated Roth portion.

Rolling to a Roth IRA: No Longer RMD-Driven

Pre-2024, the standard practitioner move was to roll Roth 401(k) balances to a Roth IRA before age 72/73 to avoid the anomalous RMD. With §325, that rationale is gone. You may still want to roll for other reasons — broader investment choices, lower fees, consolidated 5-year-clock tracking, or ERISA-vs-state creditor-protection planning — but "eliminating RMDs" is no longer a live reason for the rollover.

Roth 401(k) vs. Roth IRA Comparison

When to Roll Your Roth 401(k) to a Roth IRA

Upon separation from service: When you leave your employer, rolling your Roth 401(k) to a Roth IRA is almost always advisable. You gain investment flexibility, eliminate RMDs, and maintain all the tax-free growth benefits.

More investment options: A 401(k) typically offers 20-50 mutual funds. A Roth IRA at a major custodian offers thousands of mutual funds, all ETFs, individual stocks, bonds, and other securities. If you're an active investor or want specific holdings, the IRA is superior.

Lower fees: Many 401(k) plans charge 0.5-1.5% in annual fees (administrative, advisor, and fund fees). Roth IRAs at Vanguard, Fidelity, or Schwab often charge 0.10% or less (or nothing, if invested in index funds). Over 30 years, the fee difference compounds significantly.

The 5-year clock benefit: This is nuanced. Your Roth 401(k) has its own 5-year clock. When you roll it to a Roth IRA, the rolled amount joins your existing Roth IRA balance. The contribution portion of the rolled amount is not subject to the pro-rata rule (since it's already-taxed money). But if you have earnings in the Roth 401(k), those earnings will be subject to the Roth IRA 5-year rule for early withdrawal purposes. Rolling consolidates all your Roth balances under a single 5-year clock.

SECURE 2.0 §109 Super Catch-Up (Ages 60-63)

SECURE 2.0 §109 (effective 2025 and later) created an enhanced catch-up bracket for workers ages 60, 61, 62, and 63. Two crucial points people often get wrong:

1. It applies to all workers in that age band—regardless of income. The $145,000 (now $150,000 indexed for 2026) threshold is for the separate §603 Roth-mandate rule, not for super catch-up eligibility.
2. It replaces, not stacks with, the regular age 50+ catch-up. You get either the $8,000 regular catch-up or the $11,250 super catch-up, not both.

2026 calculation (IRS Notice 2025-67): The super catch-up is the greater of $10,000 (indexed) or 150% of the prior-year age-50 catch-up. For 2026 this remains $11,250 (same as 2025), because 150% × $7,500 (the 2025 age-50 catch-up) = $11,250. The figure is fixed by statute regardless of the $8,000 regular catch-up for 2026.

2026 elective-plus-catch-up limit, ages 60-63: $24,500 (elective deferral) + $11,250 (super catch-up) = $35,750 maximum in employee contributions. The employer's match and profit-sharing are on top of this and count toward the overall §415(c) annual-additions cap of $72,000 for 2026. Catch-up contributions sit outside §415(c) per §414(v)(3), so the full potential annual-addition is $72,000 + $11,250 = $83,250 for someone age 60–63.

Plan adoption is optional. Under final regulations (TD 10007), the super catch-up is not mandatory—individual plan sponsors can choose whether to amend their plan document to offer it. If your plan doesn't offer it, you're capped at the regular catch-up even if you're in the 60-63 window. Check with HR or your plan administrator before counting on these limits.

Roth 401(k) vs. Mega Backdoor Roth

Some 401(k) plans also offer a "mega backdoor Roth" feature—the ability to contribute after-tax dollars (beyond the $24,500 limit) up to the overall plan limit of $72,000 (2026), with immediate conversion to Roth.

A Roth 401(k) contribution is straightforward: you designate your $24,500 contribution as Roth, it's post-tax, and it grows tax-free.

A mega backdoor Roth is more complex: you contribute after-tax dollars to the traditional 401(k) (up to the $72,000 overall limit minus your regular contributions and employer match), then immediately convert those after-tax dollars to Roth. It's a Roth conversion within your plan.

Mega backdoor Roth is useful if you want to exceed the $24,500 Roth limit. Most high earners use both: max out the $24,500 Roth 401(k) contribution, then use mega backdoor Roth for an additional $47,500 post-tax contribution. Total Roth accumulation: $72,000.