⚡ Promptolis Original · Money & Finance
🏦 401(k) + IRA Optimizer — Traditional vs. Roth vs. Backdoor Decision Tree
The structured retirement-account decision system — covering the Traditional vs. Roth math based on current vs. retirement tax rate, the backdoor Roth mechanics, the Mega Backdoor Roth for high earners, and the 9-step contribution order that maximizes every dollar.
Why this is epic
Most high earners leave $10K-$50K/year of tax-advantaged space on the table because they don't understand backdoor Roth, Mega Backdoor Roth, or proper contribution ordering. This Original produces the specific 9-step contribution order for YOUR situation: emergency fund → 401k match → HSA → Traditional/Roth IRA (with backdoor mechanics) → 401k/403b → Mega Backdoor Roth → taxable.
Names the specific decision points: Traditional vs. Roth (based on current vs. expected retirement marginal rate), backdoor Roth if AGI >$161K/$240K, Mega Backdoor if 401(k) plan supports after-tax + in-plan conversion. Resolves the 'should I contribute to Roth if I'm in a high bracket?' confusion that costs people real money.
Produces the complete YEAR-BY-YEAR optimization: annual contribution order, rollover mechanics, backdoor-Roth pro-rata avoidance, HSA triple-tax-advantage usage, employer-match capture, and the 'when Roth actually makes sense' counter-intuitive cases. Based on IRS rules (current through 2026) + CFP-level tax-advantaged-account optimization.
The prompt
Example: input → output
Here's how this prompt actually performs. Real input below, real output from Claude Opus 4.
<household-income>Partner A: $220K base + $80K target bonus + $100K/year RSU grants vesting over 4 years = ~$400K effective total comp (but bonus + RSU volatile). Tech industry. Partner B: $140K salary + 10% bonus = $154K. Total household ~$554K.</household-income> <tax-bracket>Federal marginal: 35% (between $487K and $731K MFJ for 2026). California state: 9.3% marginal. Combined: ~44% marginal.</tax-bracket> <ages>Both 38. Plan to retire around 58-62.</ages> <current-accounts>Partner A 401(k): $340K. Partner B 401(k): $180K. Partner A Roth IRA: $45K (stopped direct Roth when income passed limits). Partner B Roth IRA: $38K (same). Partner A Traditional IRA: $12K (from old 401k rollover). Combined HSA: $15K. Brokerage: $220K. House equity: $450K.</current-accounts> <401k-plan-details>Partner A's plan (tech company): 50% match up to 6%. Traditional + Roth options. After-tax contributions allowed + in-plan Roth conversion (= Mega Backdoor Roth available). Partner B's plan (healthcare company): 100% match on first 4% + 50% match on next 2%. Traditional + Roth options. NO after-tax / Mega Backdoor available.</401k-plan-details> <retirement-timeline>Both targeting ~60 (22 years away). Possibly earlier if tech comp continues growing.</retirement-timeline> <expected-retirement-income>Hard to predict. Probably $180K-$250K/year in today's dollars. Mix of retirement accounts + brokerage + real estate.</expected-retirement-income> <other-considerations>HDHP = HSA eligible (currently contributing but not maxing). No self-employment income. Partner A has old employer stock at a previous company (~$50K).</other-considerations>
401(k) + IRA Optimization: Dual High-Earner Tech + Healthcare, 38yo, CA, ~$554K household
A retirement account optimization produces the specific 9-step contribution order, Traditional vs. Roth decision, backdoor mechanics, and Mega Backdoor execution calibrated to YOUR income + tax bracket + plan features. Based on IRS rules (2026) + CFP-level optimization, most high-earning couples leave $20K-$50K/year of tax-advantaged space unused because they don't know Mega Backdoor Roth or execute backdoor Roth incorrectly (pro-rata trap). Your profile — $554K household, 35% federal + 9.3% CA (44% combined), Partner A's plan supports Mega Backdoor Roth, Partner B's does not — is ideal for aggressive tax-advantaged accumulation. This optimization produces the year-by-year plan with specific contribution targets, pro-rata fix, and Mega Backdoor execution that adds ~$35K/year of Roth space you're currently missing.
Current-State Assessment
What's working:
- Both 401(k)s being funded (assumed max)
- HSA being used
- Historical Roth IRA accumulation pre-phase-out
- Brokerage accumulation for accessible savings
What's leaving money on the table:
1. Direct Roth IRA stopped. You're phased out ($240K MFJ limit for 2026). But you can do BACKDOOR Roth. $7K each = $14K/year Roth space currently unused.
2. Pro-rata rule trap. Partner A has $12K in Traditional IRA from old 401(k) rollover. This CORRUPTS backdoor Roth. Need to fix first.
3. Mega Backdoor Roth (Partner A's plan) NOT USED. Plan supports after-tax + in-plan conversion. This is $35K-$46K/year of additional Roth space. Currently $0 used.
4. HSA under-utilized. $8,300 family limit 2026 — assume you're not maxing (you said 'currently contributing but not maxing').
5. Traditional vs. Roth mix in 401(k)s may be wrong. At 44% combined marginal, Traditional wins almost certainly — verify.
Total annual tax-advantaged space currently missed: ~$48K-$62K.
Fixable. Here's how.
The 9-Step Contribution Order (For You)
In priority order for each year:
| Step | Account | Why | 2026 Limit | Your Amount |
|---|---|---|---|---|
| 1 | Both 401(k) matches | Free money | Match cap | ~$13K-$15K combined |
| 2 | HSA (max) | Triple tax advantage | $8,300 family | $8,300 |
| 3 | Traditional/Roth IRA (Partner A, backdoor) | $7K Roth space | $7,000 | $7,000 |
| 4 | Traditional/Roth IRA (Partner B, backdoor) | $7K Roth space | $7,000 | $7,000 |
| 5 | 401(k) Traditional (Partner A) | Tax defer at 44% | $23,000 | $23,000 |
| 6 | 401(k) Traditional (Partner B) | Tax defer at 44% | $23,000 | $23,000 |
| 7 | Mega Backdoor Roth (Partner A) | HUGE Roth space | Up to $46K | ~$30-38K realistic |
| 8 | Brokerage (taxable) | After tax-advantaged maxed | No limit | Remainder of savings |
| 9 | Additional options | See below | Varies | Varies |
Total tax-advantaged capacity per year (for you): ~$113K-$121K + match.
Current usage (assumed based on inputs): ~$55K. You're using about half.
Traditional vs. Roth Decision
Current marginal rate (2026): 35% federal + 9.3% CA = 44% combined
Expected retirement marginal rate:
- If retired at 60 with $200K/year income (today's dollars)
- Assume in California still (worst case for state tax)
- 2026 equivalent bracket: 24% federal at $200K-$394K MFJ + 9.3% CA = 33% combined
- If relocated to no-state-tax (FL, TX, NV): 24% federal only
Math:
- Traditional contribution today: save 44 cents per dollar
- Traditional withdrawal in retirement: pay 33 cents per dollar (CA) or 24 cents (no-state)
- Traditional wins by 11-20 percentage points.
Verdict: You should be HEAVILY Traditional, not Roth, in your 401(k) contributions. Your direct 401(k) contributions = Traditional.
The exception: if you expect LARGE tax-free income in retirement (e.g., very high brokerage growth triggering massive capital gains), some Roth hedge makes sense. But pure math favors Traditional at 44% marginal.
Where you SHOULD use Roth:
- Backdoor Roth IRA contributions ($7K each partner) — you can't use Traditional deduction anyway (phased out), so Roth is the ONLY option here
- Mega Backdoor Roth contributions — these are post-tax anyway, so they MUST be Roth
Where you should NOT use Roth:
- Direct 401(k) contributions (Traditional wins the math at 44% marginal)
HSA Strategy
Max contribution 2026 family HDHP: $8,300
Triple tax advantage:
1. Contribution deductible (save 44 cents per dollar)
2. Growth tax-free (no capital gains)
3. Withdrawal tax-free FOR MEDICAL expenses
Stealth retirement account strategy:
- Contribute max every year ($8,300 × 22 years to age 60 = $182,600 contributions + growth → potentially $500K+)
- Don't actually use for current medical expenses (pay out of pocket)
- SAVE RECEIPTS of medical expenses
- In retirement, withdraw HSA tax-free for cumulative medical expenses over the years
Your action: increase HSA to $8,300/year immediately. You're likely under-contributing.
Choose HSA provider with good investment options (Lively, Fidelity HSA). Avoid keeping HSA in cash — invest in low-cost index funds.
Backdoor Roth Mechanics
Current state: direct Roth phased out. Backdoor Roth available.
PROBLEM: Partner A has $12K in Traditional IRA (pre-tax rollover). This triggers the pro-rata rule — any backdoor conversion is partially taxable, ruining the tax-free goal.
Fix (required before executing backdoor):
Step 1: Roll Partner A's $12K Traditional IRA into her current 401(k).
- 401(k)s accept rollovers from Traditional IRAs
- This removes the pro-rata trap
- Timing: complete by Dec 31 of year you want backdoor Roth (pro-rata measured on Dec 31 balance)
Step 2: Execute backdoor Roth for both partners.
- Each partner contributes $7,000 to a Traditional IRA (non-deductible contribution — mark on Form 8606)
- Within days (ideally same week), convert entire Traditional IRA to Roth IRA
- Report on taxes via Form 8606
- Result: $7K in Roth IRA (tax-free growth forever), no pro-rata issue
Annual cadence:
- Each year in Q1: contribute $7K each to Traditional IRA, then convert to Roth
- Keep Traditional IRA at $0 balance through year (prevents pro-rata next year)
- Result: $14K/year of Roth space you're currently not using
20-year projection: $14K/year × 20 years + growth = $700K-$1.2M of tax-free Roth at retirement.
Mega Backdoor Roth Assessment
Partner A's plan supports:
- After-tax 401(k) contributions (beyond Traditional + Roth)
- In-plan Roth conversion (convert after-tax to Roth immediately)
This is the Mega Backdoor Roth. Available to about 30% of 401(k) plans. You have it. USE IT.
Mechanics:
1. Max pre-tax (Traditional) 401(k): $23,000 (2026 limit) ✓
2. Employer match: goes into Traditional 401(k) ✓
3. Total 401(k) limit 2026: $70,000 (employee + employer + after-tax)
4. Available after-tax room: $70,000 - $23,000 (Traditional) - employer match (~$9K-$13K) = ~$34K-$38K
5. Contribute after-tax to that limit
6. In-plan convert after-tax to Roth IMMEDIATELY (same day ideal — prevents growth in after-tax which would be taxable)
Partner A's annual Mega Backdoor Roth space: ~$34K-$38K
Execution:
- Set 401(k) contribution to: 100% Traditional up to $23K max, then 100% after-tax beyond
- Enable auto-conversion if plan supports (many do)
- If not auto: submit manual conversion request monthly
- Timeline: complete annual contributions by end of year to capture full space
20-year projection at $35K/year average: $700K-$1.4M of additional Roth at retirement.
Partner B's plan does NOT support Mega Backdoor. No action there — but consider lobbying HR to add it. Plans can add Mega Backdoor without full restatement.
Spousal Optimization
Coordinate across partners:
- Each partner maxes 401(k) in own plan ($23K each = $46K total)
- Partner A also uses Mega Backdoor (Partner B can't)
- Both execute backdoor Roth annually ($14K total)
- HSA is joint ($8,300 family limit — one of you contributes via your HDHP)
- Brokerage is joint (no constraint)
Total coordinated tax-advantaged: ~$113K/year + match.
Multi-Year Projection
Next 5 years (assuming income stable):
| Year | 401(k) Trad (both) | Roth IRA (backdoor) | Mega Backdoor | HSA | Total |
|---|---|---|---|---|---|
| 2026 | $46,000 | $14,000 | $35,000 | $8,300 | $103,300 |
| 2027 | ~$47,000 (limits rise) | ~$14,500 | ~$36,000 | ~$8,500 | $106,000 |
| 2028 | ~$48,000 | ~$15,000 | ~$37,000 | ~$8,700 | $108,700 |
| 2029 | ~$49,000 | ~$15,500 | ~$38,000 | ~$8,900 | $111,400 |
| 2030 | ~$50,000 | ~$16,000 | ~$39,000 | ~$9,100 | $114,100 |
| 5-Year Total | ~$543K |
Plus employer match: ~$70K over 5 years.
5-year tax-advantaged accumulation: ~$613K + growth.
Vs. current trajectory: probably ~$330K over 5 years (less Mega Backdoor + less backdoor Roth).
Gap captured by this optimization: ~$280K over 5 years.
Execution Checklist (This Year)
Quarter 1 (January):
- [ ] Confirm Partner A's plan Mega Backdoor details with HR (after-tax % + in-plan conversion process)
- [ ] Roll Partner A's $12K Traditional IRA into her current 401(k) (cleans pro-rata)
- [ ] Adjust Partner A 401(k) contribution to: 100% Traditional to $23K max, then 100% after-tax (for Mega Backdoor)
- [ ] Adjust Partner B 401(k) contribution: 100% Traditional to $23K max
- [ ] Contribute $7K each to Traditional IRAs (non-deductible)
- [ ] Convert Traditional IRAs to Roth IRAs within 14 days
- [ ] Increase HSA contribution to $8,300 (family limit)
Quarter 2 (through year):
- [ ] Monthly: verify Mega Backdoor contributions + in-plan conversions executing
- [ ] Quarterly: check balances + rebalance if needed
Year-end (December):
- [ ] Verify all limits maxed
- [ ] Confirm no Traditional IRA balance before Dec 31 (pro-rata prevention)
- [ ] Prep Form 8606 documentation for tax filing
Q1 next year:
- [ ] Repeat cycle
- [ ] Evaluate any plan changes (partner changes jobs, plan adds/removes features)
When To Get CPA Review
This year specifically:
- Pro-rata IRA rollover execution (one-time, complex)
- First Mega Backdoor execution (verify plan mechanics)
- Form 8606 preparation (backdoor Roth reporting)
CPA value: $800-$2,000 for comprehensive review. Prevents costly errors (double-taxation on improperly executed backdoor, missed pro-rata fix, wrong Form 8606).
Ongoing:
- Annual return prep (always use CPA at your income level)
- Every 2-3 years: full tax strategy review
Not needed CPA:
- Routine ongoing contributions (once set up correctly)
- HSA optimization
Key Takeaways
- You're leaving ~$48K-$62K/year of tax-advantaged space unused. Primary gaps: backdoor Roth not executed + Mega Backdoor Roth unused + HSA under-max.
- Fix pro-rata trap FIRST: roll Partner A's $12K Traditional IRA into her 401(k). Then backdoor Roth becomes clean $14K/year for both partners.
- Use Mega Backdoor Roth in Partner A's plan: ~$35K/year of additional Roth space. Plan supports after-tax + in-plan conversion. This is the biggest single optimization.
- At 44% marginal, Traditional beats Roth in 401(k) by 11-20 percentage points. Use Traditional for direct 401(k) contributions. Use Roth only for backdoor + Mega Backdoor (which are after-tax anyway).
- Get CPA review this year for pro-rata fix + first Mega Backdoor execution + Form 8606 prep. $800-$2,000 cost prevents costly errors. Then annual cadence is self-manageable.
Common use cases
- Mid-to-high earners ($150K-$500K household) optimizing retirement contributions
- Young professionals starting first 401(k) deciding Traditional vs. Roth
- Executives with complex comp (RSUs, bonuses) optimizing timing
- Dual-income couples coordinating across two 401(k)s + IRAs
- Self-employed (solo 401k, SEP-IRA, Simple IRA decisions)
- Backdoor Roth aspirants navigating pro-rata rule
- Mega Backdoor Roth candidates at companies with compatible plans
- High-income earners phased out of direct Roth contributions
- Near-retirees evaluating Roth conversion strategies
Best AI model for this
Claude Opus 4 or Sonnet 4.5. Retirement account optimization requires tax math, IRS rule fluency, and individual-situation reasoning. Top-tier reasoning matters. Not tax advice — consult a CPA for your specific situation.
Pro tips
- ALWAYS capture 401(k) match first. If you get 50% match on 6% contribution, that's a guaranteed 50% return. Beats any other investment. Never leave match on the table.
- Traditional vs. Roth is decided by ONE question: will your marginal rate be HIGHER or LOWER in retirement than today? Higher in retirement → Roth today. Lower in retirement → Traditional. Most mid-high earners in their 30s-40s have HIGHER rates now → Traditional wins. But: exceptions matter.
- HSA is the single best account if you have high-deductible health plan. Triple tax advantage: deductible contributions + tax-free growth + tax-free withdrawals for medical. Use it as a stealth retirement account — save receipts, withdraw tax-free in retirement for cumulative medical expenses.
- Backdoor Roth: contribute non-deductible to Traditional IRA, then convert to Roth same year. Bypasses the $161K/$240K income limit. BUT: pro-rata rule ruins this if you have pre-tax IRA balances. Roll those into 401(k) first.
- Mega Backdoor Roth: after-tax 401(k) contributions + in-plan Roth conversion OR in-service distribution to Roth IRA. Can add $30K-$46K/year of Roth space. Only works if your 401(k) plan supports it — not all do.
- Don't forget SPOUSAL IRA. Non-working or low-earning spouse can contribute to IRA based on household income. Easy extra $7K/year of tax-advantaged space.
- Roth conversions during low-income years (between jobs, early retirement, sabbatical) are gold. Fill lower brackets with conversions. Average marginal rate on $20K conversion at 12% bracket vs. 32% later = free 20% tax savings.
- For 401(k): max out the match + Traditional to bring down current taxable income + Roth portion if plan offers + Mega Backdoor if available. Most plans give you all 3 options in varying forms. Use them.
Customization tips
- Print the 9-step contribution order and keep it visible during annual financial reviews. Every year in January, walk through it and confirm each step is funded at max (or conscious reason it isn't).
- If your 401(k) plan DOESN'T support Mega Backdoor Roth, ask HR to add it. Many plans will — it's a relatively simple plan amendment. Saving $15K-$35K/year of Roth space is worth the ask.
- For backdoor Roth, execute the conversion within days of the Traditional IRA contribution. If you let money sit in Traditional IRA and gain value, the gains get taxed on conversion. Fast conversion = clean.
- Don't move backdoor Roth funds into same Traditional IRA account year-over-year. Use a dedicated Traditional IRA for backdoor conversions, empty at year-end. Prevents accidental pro-rata triggers.
- Roth conversions in between-job years (unemployment, sabbatical, gap year before retirement) are gold. Fill lower tax brackets (12%, 24%) with conversions. Saves material dollars if executed well. Worth planning a year in advance.
Variants
High-Earner Mode
For $250K+ household income. Emphasizes backdoor Roth mechanics, Mega Backdoor Roth, phase-out navigation.
Young Professional Mode
For $80K-$200K earners starting out. Emphasizes 401(k) match capture, Traditional vs. Roth decision, foundation building.
Self-Employed Mode
For freelancers, consultants, business owners. Solo 401(k), SEP-IRA, Simple IRA decision tree.
Pre-Retirement Mode
For people within 10 years of retirement. Roth conversion ladders, bridge strategies, RMD planning.
Frequently asked questions
How do I use the 401(k) + IRA Optimizer — Traditional vs. Roth vs. Backdoor Decision Tree prompt?
Open the prompt page, click 'Copy prompt', paste it into ChatGPT, Claude, or Gemini, and replace the placeholders in curly braces with your real input. The prompt is also launchable directly in each model with one click.
Which AI model works best with 401(k) + IRA Optimizer — Traditional vs. Roth vs. Backdoor Decision Tree?
Claude Opus 4 or Sonnet 4.5. Retirement account optimization requires tax math, IRS rule fluency, and individual-situation reasoning. Top-tier reasoning matters. Not tax advice — consult a CPA for your specific situation.
Can I customize the 401(k) + IRA Optimizer — Traditional vs. Roth vs. Backdoor Decision Tree prompt for my use case?
Yes — every Promptolis Original is designed to be customized. Key levers: ALWAYS capture 401(k) match first. If you get 50% match on 6% contribution, that's a guaranteed 50% return. Beats any other investment. Never leave match on the table.; Traditional vs. Roth is decided by ONE question: will your marginal rate be HIGHER or LOWER in retirement than today? Higher in retirement → Roth today. Lower in retirement → Traditional. Most mid-high earners in their 30s-40s have HIGHER rates now → Traditional wins. But: exceptions matter.
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