Mega Backdoor Roth 2026: How High Earners Can Contribute Up to $47,500 to Tax-Free Retirement Using the §415(c) Annual Additions Limit

Why the Mega Backdoor Roth Is the Most Underused Tax-Free Growth Vehicle in 2026

Most high-earning U.S. workers know that the regular 401(k) elective-deferral limit for 2026 is $24,500, and that the IRA limit is $7,500. Far fewer realize that the Internal Revenue Code, in IRC §415(c), sets a much larger ceiling on the total dollars that can flow into a defined contribution plan in a single year — for 2026, $72,000 per IRS Notice 2025-67 and IR-2025-111. The gap between the elective-deferral cap and the §415(c) cap — sometimes called the "after-tax bucket" — is where the mega backdoor Roth lives. For a worker with no employer match, the bucket is $72,000 − $24,500 = $47,500. With an employer match of $7,500, it shrinks to $40,000. With a 25 % match on a $200,000 salary, it shrinks again to $25,000. Every dollar of that bucket can — if your plan is designed correctly — be converted to a Roth account and grow tax-free for the rest of your life.[5, 1, 2]

For a 35-year-old earning $300,000 who maxes the after-tax bucket at $40,000/year (assuming a typical $7,500 employer match), assumes a 7 % real return, and converts each contribution to Roth promptly, the strategy compounds to roughly $3.9 million in tax-free wealth by age 65 — a figure that does not appear on any standard 401(k) statement and that most financial-planning websites quietly omit because the strategy depends on a plan-design feature only a fraction of employers offer. Vanguard's "How America Saves 2025" report — which analyzed nearly 5 million defined-contribution plan participants — confirms that adoption of after-tax contributions and in-plan Roth conversions, while growing, remains concentrated at large-employer plans (Fortune 500, large tech, and big-financial-services firms). The Plan Sponsor Council of America's 67th Annual Survey of 401(k) plans similarly shows that fewer than one in five plans nationwide currently allow after-tax contributions plus in-plan Roth conversions — making this one of the genuinely under-utilized tax shelters in the U.S. retirement system.[28, 29]

Three regulatory shifts have made 2026 the inflection year for revisiting this strategy. First, the §415(c) limit jumped from $70,000 (2025) to $72,000, expanding the after-tax bucket. Second, the SECURE 2.0 Act's §603 Roth-catch-up mandate took effect on January 1, 2026 — and while the mandate technically governs only catch-up dollars (the $8,000 / $11,250 layer), the final regulations issued September 15, 2025 (T.D. 10026, 90 FR 39855) reshape the broader Roth-source mechanics that the mega backdoor depends on. Third, the One Big Beautiful Bill Act (P.L. 119-21, signed July 4, 2025) permanently locked in the TCJA-era individual brackets at 10/12/22/24/32/35/37 % — removing the prior "convert before the 2028 sunset" urgency and shifting the calculus toward steady-state Roth funding rather than rate-arbitrage conversions. The mega backdoor is now best understood not as a hedge against future rate hikes, but as a compounding-engine play: a way to push an extra $25,000-$47,500/year into a vehicle whose growth never gets taxed, ever.[3, 4, 25, 27]

This guide walks through the full strategy in twelve sections: the §415(c) math, the plan-design requirements that decide whether you can use it at all, step-by-step execution timing, the in-plan-conversion-vs-Roth-IRA decision tree, the Form 1099-R reporting machinery, the ACP-test compliance trap that quietly disables the strategy at smaller employers, the SECURE 2.0 §603 interaction, the OBBBA-era long-term planning lens, three concrete case studies, the most common pitfalls, and ten of the questions readers most often send us. Use our compound interest calculator alongside each section to project the exact long-run wealth impact of the after-tax dollars you can actually channel through your plan in 2026.

The §415(c) Math: Decomposing the $72,000 Annual Additions Limit for 2026

The mega backdoor Roth is a story about three IRC sections fitting together. §402(g) caps your elective deferrals at $24,500 in 2026 (or $32,500 with the 50+ catch-up; $35,750 with the 60-63 super catch-up). §401(m) governs employer matching contributions and after-tax employee contributions. §415(c) sits on top of both and limits the total annual additions — the sum of (i) all employee elective deferrals (whether traditional or Roth), (ii) all employer contributions (match, profit-share, nonelective), and (iii) all after-tax employee contributions, plus forfeitures — to the lesser of $72,000 or 100 % of compensation per IRC §415(c)(1). Catch-up contributions under §414(v) are explicitly excluded from §415(c), so the all-in ceiling rises to $80,000 for 50+ workers and $83,250 for ages 60-63.[5, 6, 7, 1]

A worked example clarifies the bucket sizes. Take a 35-year-old engineer earning $300,000 with an employer match formula of "100 % of the first 4 % deferred." Her 4 %-of-pay deferral is $12,000, but she chooses to max her elective deferral at $24,500. The match on $24,500 deferred is capped at $12,000 (because the match formula is on her first 4 % of pay only — $300,000 × 4 % = $12,000), regardless of how much she defers. So her §415(c) bucket fills as follows: (a) elective deferral $24,500 + (b) employer match $12,000 = $36,500 used. The remaining bucket is $72,000 − $36,500 = $35,500 of after-tax space. If she also receives a 3 % nonelective profit-share, that adds $9,000 and reduces the after-tax space to $26,500. The exact arithmetic is plan-specific and worth running every January when the COLA limits change.[5, 19]

Two non-obvious arithmetic features matter. First, the $72,000 limit is per employer plan, not per worker. A participant with two unrelated employers — say, a W-2 day job and a self-employed consulting Solo 401(k) — has two separate §415(c) buckets, each capped at $72,000, even though the §402(g) elective-deferral cap of $24,500 is aggregated across all plans (per §402(g)(1)(A)). For the rare worker who has access to two unrelated plans, the after-tax bucket can sum to $144,000 in 2026. Second, the 100-%-of-compensation alternative cap matters for low-base/high-bonus workers. A $50,000-base worker who receives a $100,000 bonus has W-2 compensation of $150,000 and is therefore not constrained by 100 %; but a $40,000-base worker maxing the elective deferral has only $40,000 of compensation against the §415(c) cap, hard-stopping the bucket at $40,000 minus their employer match.[5, 6]

Plan Requirements: Without These Two Features, the Strategy Is Impossible

A 401(k), 403(b), or governmental 457(b) plan must contain two distinct features for the mega backdoor Roth to work. Feature 1 — After-Tax (Non-Roth) Contributions: the plan document must affirmatively allow employees to contribute on an after-tax basis above and beyond the §402(g) elective-deferral cap. These are not Roth elective deferrals (which are capped at the same $24,500 §402(g) limit and are taxed under §402A); they are a separate "after-tax" source-money type that exists outside the elective-deferral architecture. Feature 2 — Roth Conversion Mechanism: the plan must allow you to move those after-tax dollars to Roth — either via an in-plan Roth conversion under IRC §402A(c)(4) (subject to IRS Notice 2010-84 as modified by Notice 2013-74) or via an in-service distribution to a personal Roth IRA under IRC §401(a)(31).[6, 16, 17, 8]

You can confirm both features in three ways. (1) Read the Summary Plan Description (SPD) — every ERISA-covered plan provides one annually. Search for the strings "after-tax contributions," "voluntary after-tax," "in-plan Roth conversion," or "in-service distribution." (2) Call your plan administrator and ask the two questions verbatim: "Does the plan permit after-tax (non-Roth) employee contributions in excess of the §402(g) limit?" and "Does the plan permit either in-plan Roth conversions or in-service distributions of after-tax money to a Roth IRA before age 59½?" Get the answer in writing. (3) For self-employed Solo 401(k) holders, check whether your plan custodian (Fidelity, Schwab, E*TRADE, Vanguard, etc.) actually offers an "after-tax-friendly" Solo 401(k) document — most do not by default; you may need a third-party plan provider such as MySolo401k, Carry, or a custom ERISA-prototype to enable both features.[22, 20]

A frequent confusion: a plan that allows Roth elective deferrals ("designated Roth contributions" under §402A) does not automatically allow after-tax non-Roth contributions. These are different source-money types governed by different IRC sections — Roth elective deferrals fill the same $24,500 bucket as traditional pretax deferrals (you simply choose the tax flavor), while after-tax contributions are a third bucket that flows from compensation that has already been taxed and gets reported in Box 12 of Form W-2 with a different code. About 76 % of large 401(k) plans now offer designated Roth contributions (Vanguard 2025), but only roughly 20-25 % offer after-tax contributions plus in-plan Roth conversions (PSCA 67th Annual Survey). The mega backdoor Roth requires the rarer combination, and many participants believe they have access when they only have access to Roth deferrals.[28, 29, 6]

Step-by-Step Execution: A Month-by-Month 2026 Playbook

The execution sequence has four moving parts that must be timed correctly. Step 1 (January-March): maximize regular elective deferrals. Set your contribution rate so that you hit the full $24,500 §402(g) limit by year-end (a $300,000 earner with bi-weekly pay would set 6.4 % deferral; a $500,000 earner could set 4 % and front-load to hit the limit by Q3 if their plan allows true-up matching). The catch-up dollars ($8,000 for 50+, $11,250 for 60-63) sit on top and must be Roth-flavored if your prior-year FICA wages exceeded $150,000 per Notice 2025-67. Step 2 (parallel): enroll in after-tax non-Roth contributions. Set the percentage so that — combined with your elective deferral, employer match, and any profit-share — you hit but do not exceed the $72,000 §415(c) cap by December.[1, 5]

Step 3 (immediately after each after-tax contribution): convert. The mathematical reason matters: any earnings on after-tax dollars between the contribution and the conversion are pretax money and become taxable when converted. A $1,000 after-tax contribution that grows to $1,050 in three weeks before conversion produces $50 of taxable income, plus $1,000 of basis recovery that flows tax-free into the Roth side. If you convert weekly or monthly (a feature called "auto-conversion" by some recordkeepers like Fidelity NetBenefits, Schwab Workplace Retirement, and Empower), the taxable earnings are negligible. If you convert annually, six months of S&P 500 returns can produce thousands of dollars of unnecessary tax. Push for the most-frequent conversion cadence your plan allows — preferably automatic.[19, 15]

Step 4 (year-end and tax-filing season): verify the conversions. By January 31, 2027, you should receive Form 1099-R(s) reporting the conversions for tax year 2026. Cross-check Box 1 (gross distribution), Box 2a (taxable amount — should be only the earnings, not the after-tax basis), Box 5 (employee contributions / designated Roth contributions / insurance premiums — this is where the after-tax basis appears), and Box 7 (distribution code — see Section 6 of this guide). The taxable amount in Box 2a flows onto Form 1040, line 5b. The IRS does not require a separate Form 8606 for in-plan Roth conversions of qualified-plan after-tax money (Form 8606 is for IRA basis), but if you instead distributed to a Roth IRA, the after-tax basis on the way out is treated as basis in the receiving Roth IRA — and you should keep the 1099-R indefinitely as proof should the IRS ever question the basis years later.[13, 11]

In-Plan Roth Conversion vs. In-Service Distribution to a Personal Roth IRA: A Decision Tree

Once after-tax money is in the plan, you have two paths to Roth status. Path A — In-Plan Roth Conversion (IPRC): under IRC §402A(c)(4), the after-tax dollars are reclassified inside the plan as a designated Roth account. They never leave the plan trust; you simply hit a button on the recordkeeper portal. The 1099-R uses Distribution Code G (direct rollover) per the IRS Form 1099-R Instructions. Path B — In-Service Distribution to Roth IRA: under IRC §401(a)(31) and the allocation rules of IRS Notice 2014-54, the after-tax dollars (and any associated earnings) are distributed out of the plan; the after-tax basis is rolled into a personal Roth IRA, and any earnings can be split off into a Traditional IRA to avoid current taxation. The 1099-R uses Distribution Code G as well, with Box 5 showing the after-tax basis amount.[6, 16, 15, 8, 13]

Six factors decide between the two paths. (1) Five-year clock: an in-plan Roth conversion starts a fresh five-year clock under §402A(d)(2) for that designated Roth account; an in-service distribution to a Roth IRA piggybacks on the existing five-year clock from your first Roth IRA contribution (per §408A), which for many savers started years or decades earlier. (2) Investment menu: an in-plan Roth account is constrained to the plan's fund lineup (often institutional-class index funds at very low expense ratios — a meaningful advantage for the next 30 years); a Roth IRA gives you the entire investable universe (individual stocks, low-cost ETFs, even private alternatives via specialized custodians). (3) Creditor protection: ERISA-covered plan accounts have unlimited federal anti-alienation protection under 29 U.S.C. §1056(d)(1); Roth IRAs have only the bankruptcy protection cap currently $1,711,975 (2025-2028 cycle, indexed) under 11 U.S.C. §522(n).[6, 23]

(4) Required Minimum Distributions: starting January 1, 2024, Roth designated accounts inside a 401(k) no longer have lifetime RMDs (SECURE 2.0 §325) — but for the participant's lifetime only; beneficiaries may face the 10-year inherited-Roth rule. Roth IRAs have never had lifetime RMDs. Either path is now RMD-free during life. (5) Conversion frequency: in-plan conversions can usually be automated weekly or monthly, eliminating earnings drag (the 6-month annual cycle commonly seen with in-service distributions can produce hundreds-to-thousands of taxable dollars). (6) Estate planning: Roth IRAs allow more flexibility for beneficiary designations and stretch-style estate planning under the post-SECURE 2.0 EDB rules; in-plan Roth balances flow under plan distribution rules and may not allow trust-as-beneficiary or split designations as cleanly. The most common winning configuration for high earners under 50 is in-plan conversion every payroll cycle, then a one-time rollover to a personal Roth IRA at job change or retirement.[11, 12]

Tax Reporting: Form 1099-R Codes G and H, Form 5498, and When Form 8606 Is Required

The conversion mechanics produce specific 1099-R codes, and getting them wrong is the most common source of incorrectly-prepared mega backdoor Roth tax returns. Per the 2025 IRS Form 1099-R Instructions (which apply to 2026 distributions and reporting): Distribution Code G denotes "Direct rollover and direct payment" — used when after-tax dollars in a 401(k) are directly converted to the designated Roth 401(k) (in-plan Roth conversion), or when after-tax dollars are directly rolled over to another retirement plan. The 1099-R will show Box 1 (gross distribution) = total amount converted, Box 2a (taxable amount) = $0 if there are no earnings, Box 5 (employee contributions/designated Roth contributions/insurance premiums) = after-tax basis amount, and Box 7 = G. Distribution Code H denotes "Direct rollover of a designated Roth account distribution to a Roth IRA" — used only when an existing designated Roth 401(k) balance is rolled to a Roth IRA. Code H is not used for the initial after-tax-to-Roth conversion.[13, 19]

A two-step strategy — first move after-tax to designated Roth 401(k) via in-plan conversion (Code G), then later roll the designated Roth balance to a Roth IRA at job change (Code H) — produces two separate 1099-Rs in different tax years. Both must be reported on Form 1040 lines 5a (gross distribution) and 5b (taxable portion), but in most cases the taxable portion is zero because the conversion was performed promptly with no taxable earnings. The IRS does not require Form 8606 for in-plan Roth conversions of qualified-plan after-tax money — Form 8606 is for nondeductible IRA basis tracking under §408(o). However, if you do a traditional backdoor Roth IRA in the same year (separate from the mega backdoor in your 401(k)), Form 8606 is required for that — many high earners file 8606 every year regardless to track IRA basis cleanly.[9, 11]

The ACP Test Trap: Why Some Employers Quietly Disable the Mega Backdoor

Among the IRS's nondiscrimination rules for qualified plans, the Actual Contribution Percentage (ACP) test compares the average rate of after-tax contributions plus employer matching contributions made by Highly Compensated Employees (HCEs — earners above $160,000 in 2025 / $165,000 indexed for 2026) versus Non-Highly Compensated Employees (NHCEs). If HCE participation in after-tax contributions outpaces NHCE participation by too much (the gateway is roughly 2 percentage points or 125 % of NHCE rate, whichever is greater), the plan fails the ACP test, and HCE excess after-tax contributions must be returned with earnings by March 15 of the following year — eliminating the mega backdoor benefit entirely. Many small and mid-size employers either (a) avoid offering after-tax contributions at all because of ACP failure risk, or (b) offer them but cap HCE after-tax deferrals at a low percentage to keep the test passing. Plans that adopt a safe-harbor 401(k) design under IRC §401(k)(12) or §401(k)(13) are exempt from the ADP test but not the ACP test as it applies to after-tax contributions, leaving the ACP risk in place.[20, 5]

Three implications follow. First, the mega backdoor Roth is most reliably available at large employers with broad NHCE participation (Fortune 500, big tech, big finance, top consulting firms, large universities) — exactly the sectors where the strategy is most discussed in employee Slack channels. Second, smaller employers occasionally allow it but the HCE participants face a March-15 surprise refund risk. Third, Solo 401(k) holders sit outside the ACP test entirely because the plan covers only owner-employees (no NHCE comparator group exists), making this the easiest path for self-employed high earners. The trade-off: you must establish the Solo 401(k) with a custodian or third-party plan provider that supports after-tax contributions plus in-plan Roth conversions, which most prototype documents (Fidelity, Schwab default Solo 401(k)) do not.[20, 14]

SECURE 2.0 §603 Roth Catch-Up Mandate: How It Interacts with the Mega Backdoor in 2026

Effective January 1, 2026, SECURE 2.0 §603 amended IRC §414(v)(7) to require that any catch-up contribution (the $8,000 / $11,250 layer) made by a participant whose prior-year FICA wages from the same employer exceeded an indexed threshold must be designated as a Roth (after-tax) contribution. The 2026 wage threshold is $150,000 per IRS Notice 2025-67 (up from the statutory base of $145,000), based on 2025 FICA wages. The Treasury and IRS finalized the implementing regulations on September 15, 2025; the final regs at Treas. Reg. §1.414(v)-2 were published in the Federal Register on September 16, 2025 (T.D. 10026, 90 FR 39855). Plans have a "reasonable, good-faith" compliance window through December 31, 2026.[3, 4, 1, 7, 24]

Critically, §603 governs the catch-up dollars only — the $8,000 (age 50-59 or 64+) or $11,250 (age 60-63) layer. After-tax non-Roth contributions in the §415(c) bucket between $24,500 and $72,000 are not catch-up contributions and are not subject to the §603 mandate; they remain a separate source-money type that the participant chooses to convert via the mega backdoor. However, the final regulations clarify two structural points that ripple into mega-backdoor practice. First, the "wage threshold from the same employer" prevents aggregation across multiple W-2s from unrelated employers — meaning a worker with two unrelated jobs each below $150,000 escapes the Roth catch-up mandate even though combined wages exceed it. Second, plans may now use "deemed Roth elections" to automatically classify catch-up dollars as Roth for affected employees, eliminating per-payroll opt-in friction. Both changes make 2026 the first year where high earners must explicitly think about the catch-up tax flavor and the after-tax bucket as separate decisions.[4, 3]

OBBBA 2025 and the Long-Term Strategic Lens: Why Mega Backdoor Still Wins

The One Big Beautiful Bill Act (P.L. 119-21, signed July 4, 2025) permanently locked the TCJA-era individual brackets at 10/12/22/24/32/35/37 % and made permanent the larger standard deduction. For high earners, this changes the strategic calculus around Roth conversions in two ways. First, the long-feared "TCJA sunset" of December 31, 2025 — which would have reverted brackets to 10/15/25/28/33/35/39.6 % — never happened. Advisors who had urged front-loaded Roth conversions before the sunset must now reframe: there is no rate-arbitrage urgency, and the decision becomes a steady-state question of expected retirement bracket vs. current bracket. Second, OBBBA introduced a new 35-percent effective itemized-deduction cap on top-bracket taxpayers (Form 1040 Schedule A interactions for 37%-bracket earners), which slightly increases the effective marginal rate on labor income relative to retirement-account growth — making tax-free compounding even more attractive on a relative basis. Per the CRS Report R48611 and the Tax Foundation OBBBA FAQ, the bill's individual provisions do not directly modify retirement contribution limits or the §415(c) cap.[25, 27, 30]

OBBBA also raised the federal estate-and-gift-tax exemption to $15 million per person from 2026 (indexed thereafter), making intergenerational Roth assets even more valuable. Roth IRAs and inherited Roth 401(k) balances pass to beneficiaries free of income tax (subject to the post-SECURE 2.0 10-year rule for non-eligible-designated-beneficiaries), and the larger estate exemption removes federal estate-tax friction for most affluent households. The strategic implication: a 35-year-old funding $40,000/year through the mega backdoor for 30 years builds roughly $3.9M of tax-free wealth that, if not consumed in retirement, can pass to heirs entirely outside the income-tax system and (for households below $30M for couples) outside the federal estate-tax system. Few other vehicles allow tax-free wealth transfer at this scale, which is why high-net-worth advisors increasingly treat the mega backdoor not as a retirement tool but as the most efficient form of tax-advantaged generational wealth transfer available to W-2 earners.[25, 30, 27]

Three Real-World Cases: When to Use the Mega Backdoor and When to Skip It

Case 1 — 35-year-old software engineer, $250,000 W-2 income, single, big-tech employer: plan offers after-tax + auto-conversion. Maxes elective deferral $24,500; receives $12,000 employer match (4 % of pay capped at $300K compensation × 4 %); contributes $35,500 after-tax (= $72,000 − $24,500 − $12,000); auto-converts each pay period. After 30 years at 7 % real return, the $35,500/year produces approximately $3.5M of tax-free Roth wealth. Recommendation: full execution. The strategy is essentially free money for someone in this profile.

Case 2 — 45-year-old dual-income married couple, $400,000 combined W-2, two children, mid-size employer plans: only one spouse's plan offers after-tax + in-service distributions; the other plan is a basic safe-harbor design. The accessible spouse maxes elective deferral $24,500 + after-tax bucket fully; the inaccessible spouse maxes elective deferral $24,500 only. Combined Roth IRA backdoor (2 × $7,500 = $15,000) plus the working spouse's after-tax stack of ~$36,000 channels approximately $76,000/year of fresh Roth-source dollars in addition to traditional 401(k) deferrals. Recommendation: full execution on the accessible plan, lobby HR at the inaccessible plan to add after-tax provisions (some employers add it after employee surveys; the Vanguard 2025 data shows after-tax adoption is the fastest-growing plan-design feature among Fortune 500 sponsors).[28]

Case 3 — 55-year-old self-employed consultant, $200,000 net Schedule C income, Solo 401(k) holder: as a sole-proprietor with no employees, the participant is not subject to ACP testing and can self-design the Solo 401(k) to allow after-tax contributions and in-plan Roth conversions. Maxes employee elective deferral $24,500 + age-50 catch-up $8,000 = $32,500 (the catch-up is Roth-mandated under §603 because Schedule C earnings exceed the $150K threshold — although technically Schedule C self-employment income is not "FICA wages from the same employer" subject to §603, the final regs clarified the self-employed exemption per 90 FR 39855). Employer (sole-proprietor self) makes a discretionary $40,000 employer contribution; remaining §415(c) bucket = $72,000 − $24,500 − $40,000 = $7,500 for after-tax. Plus the IRA backdoor adds $7,500. Recommendation: full execution, with attention to the Solo 401(k) document language — most stock prototypes from Fidelity / Schwab do NOT support after-tax contributions; you may need MySolo401k, Carry, or a custom Solo 401(k) provider.[14, 4]

Common Pitfalls: The Six Mistakes That Quietly Wreck the Strategy

(1) Confusing Roth elective deferrals with after-tax contributions — these are different source-money types; only true after-tax contributions feed the §415(c) bucket above the $24,500 elective-deferral limit. (2) Delaying conversions and incurring taxable earnings — six months of S&P 500 returns on $40,000 of after-tax money produces ~$1,400 of unnecessary taxable income; aim for weekly or monthly auto-conversion. (3) Triggering ACP test failure — many small-employer plans cap HCE after-tax deferrals (e.g., 5% of pay) for this reason; never assume the plan-document language matches what the recordkeeper portal allows. (4) Forgetting the §415(c) limit and over-contributing — excess after-tax contributions must be returned with earnings, and the earnings are taxable; recordkeepers typically auto-stop deferrals when the §415(c) cap is hit, but not always.[5, 20]

(5) Misreporting Form 1099-R — confusion between Codes G and H, and failure to recognize that Box 5 (after-tax basis) reduces the Box 2a taxable amount, frequently produces inflated tax bills; the IRS sometimes issues CP-2000 notices that confuse this further. Keep your 1099-R, the contribution confirmations, and the conversion confirmations together. (6) Missing the in-service distribution age window — some plans only allow after-tax distributions after age 59½, eliminating the in-service Roth-IRA path during one's peak career years; in-plan conversion remains available regardless of age, so the in-plan path is more universally accessible. Always check the plan document for the actual distribution-event language: typical triggers include severance from service, age 59½, hardship (rarely useful), and "any time" for after-tax sources (the language to look for).[13, 19]

Frequently Asked Questions

The questions below are the ones readers most commonly send us about the mega backdoor Roth — focused on 2026 mechanics, rule changes, and edge cases that surface only when you actually try to execute the strategy.