TCJA Expires December 31, 2025
Is Your Retirement Plan Ready for Higher Tax Brackets?
The Tax Cuts and Jobs Act (TCJA) sunsets at the end of 2025. Unless Congress acts:
- Tax brackets increase across the board (22% → 25%, 24% → 28%)
- Standard deduction gets cut nearly in half ($29,200 → ~$15,000 for married couples)
- Personal exemptions may return (complicating planning further)
Then OBBBA’s senior deduction phases in (2026-2028), creating a narrow window where strategic planning can save six figures in lifetime taxes.
Your retirement calculator needs to handle this transition. Most can’t.
The 2025-2028 Tax Planning Window
2024-2025: The TCJA Window
Current lower brackets are still in effect.
- Roth conversions at 22% instead of 25%
- Lower marginal rates on retirement income
- Larger standard deduction shields more income
Action: Accelerate Roth conversions, realize capital gains, take bonuses - while brackets are low.
2026: TCJA Expires + OBBBA Year 1
Tax brackets jump. OBBBA senior deduction begins (for those 65+).
- Married couples lose ~$14,000 in standard deduction
- But seniors gain OBBBA deduction ($4,000 in 2026)
- Net effect: most retirees see tax increase
Action: Understand your new effective rate. Rebalance withdrawal strategy.
2027-2028: OBBBA Transition
Senior deduction increases year by year.
- 2027: $6,500 senior deduction
- 2028: Full $10,000 senior deduction
- Post-2028: Unknown (depends on future legislation)
Action: Optimize timing of income, conversions, and withdrawals around changing deductions.
Why Most Retirement Calculators Will Fail You
They have hardcoded 2024 tax brackets.
When TCJA expires, their projections become obsolete overnight. You’ll wait 6-18 months for a vendor update - if it ever comes.
They can’t model OBBBA.
The senior deduction phases in over 3 years (2026-2028). Generic calculators have no way to handle this transition.
They don’t let you edit tax parameters.
Tax laws will change again in 2027, 2028, 2030. You need software that adapts when Congress acts - not software that becomes a paperweight.
How Fatboy Handles Tax Law Changes
Editable Tax Parameters (Pro Feature)
Federal Brackets: Edit marginal rates, income thresholds, standard deduction amounts State Taxes: Model your state’s brackets (or compare states if you’re planning a move) OBBBA Senior Deduction: Built-in support for the 2026-2028 phase-in schedule Future Changes: When tax laws change in 2027-2028, you update the software yourself in 10 minutes
You’re not dependent on a vendor. You control the assumptions.
Side-by-Side Scenario Comparison
Run the same retirement plan under different tax regimes:
- Scenario A: TCJA remains permanent (baseline)
- Scenario B: TCJA expires as scheduled (current law)
- Scenario C: Partial TCJA extension (compromise scenario)
- Scenario D: Your own assumption based on political landscape
See exactly how each scenario impacts your:
- After-tax retirement income
- Roth conversion strategy
- Withdrawal sequencing
- Total lifetime taxes paid
Year-by-Year Tax Projections
Fatboy doesn’t just give you a “probability of success” number. It shows:
- Your effective tax rate every single year from now to age 95
- Federal and state taxes owed each year
- How TCJA expiration + OBBBA phase-in changes your rate
- Exactly where you land in the brackets (22% vs 24% vs 25% matters)
Real Tax Transition Scenarios
Scenario 1: The Front-Load Strategy Convert $200k to Roth in 2024-2025 at 22-24% brackets, before expiration pushes you to 25-28% brackets
Scenario 2: The OBBBA Optimization Model retirement at 64 vs 65 vs 66 to maximize senior deduction availability during the transition years
Scenario 3: The State Tax Arbitrage Compare retiring in California (9.3% state tax) vs Texas (0%) vs Florida (0%) under post-TCJA federal rates
Scenario 4: The Withdrawal Sequencing Shift Withdraw from taxable accounts in 2024-2025, then switch to Roth after TCJA expires to minimize lifetime taxes
Scenario 5: The “What If Congress Extends TCJA” Hedge Build two plans: one assuming expiration, one assuming extension. Stress test both.
What Makes Fatboy Different
Tax Laws Changed in July 2025. Your Calculator Shouldn't Be Stuck in 2024.
When OBBBA passed, most retirement software became obsolete overnight. Fatboy users updated their tax parameters in 10 minutes and kept planning.
Tax laws will change again. Probably in 2027-2028. When they do, you'll be ready. Read why editable parameters matter →
Professional Tax Planning Tools - No Advisor Fee Required
You don’t need a financial advisor to charge you 1% AUM ($10,000/year on $1M) to model TCJA expiration impacts.
You need the same software advisors use.
Fatboy gives you:
- Editable federal and state tax parameters
- TCJA expiration modeling built-in
- OBBBA senior deduction support (2026-2028)
- Roth conversion optimization across changing tax regimes
- Monte Carlo simulations to stress test your plan
- Professional PDF reports for your CPA or tax advisor review
One-time purchase. You own it. No subscriptions.
See Tax Planning Analysis in Action
Compare your retirement plan under current law (TCJA expires) vs TCJA extension scenarios
Pricing
Free Version: Full tax planning capability. Model TCJA expiration impacts. 3 scenarios. Core features unlocked.
Pro Version - $149 (One-Time):
- Editable tax parameters (TCJA, OBBBA, state taxes - you control it)
- Unlimited scenarios (compare dozens of tax strategies)
- Advanced Roth conversion optimization
- Monte Carlo simulations
- Professional PDF reports
- Sensitivity analysis (see which assumptions actually matter)
- All future updates included
No subscriptions. Ever.
System Requirements
Desktop application (Windows 10/11 fully supported, Linux beta, macOS coming soon).
Your data stays on your computer. No cloud sync. No harvesting your financial information.
Get Started
Model the TCJA expiration impact on your retirement plan. See exactly how 2026 tax changes affect your strategy. Upgrade to Pro when you need editable tax parameters and unlimited scenarios.
Frequently Asked Questions
Q: What if Congress extends TCJA before it expires? A: You edit the tax brackets yourself to reflect the extension. Takes 10 minutes. Keep planning.
Q: Can this model the OBBBA senior deduction phase-in (2026-2028)? A: Yes. Pro version has OBBBA parameters built-in. You can edit the deduction amounts by year.
Q: Does it handle state taxes? A: Yes. State tax brackets are fully editable. Model your state’s rates under different scenarios.
Q: Can I compare multiple tax law scenarios side-by-side? A: Yes. Run one scenario with TCJA expiration, another with extension, another with your own assumptions. See exactly what changes.
Q: What if I’m not sure what tax law changes are coming? A: Model multiple scenarios. Stress test your plan under optimistic, pessimistic, and baseline assumptions. See where your plan breaks.
Q: Can I share this with my CPA? A: Yes. Pro version exports professional PDF reports with full tax projections. Email them to your CPA for review and collaboration.
Questions? Email: fbfinancialplanner@gmail.com