The Looming Statutory Reversion
The Tax Cuts and Jobs Act (TCJA) of 2017 enacted sweeping changes across corporate and individual tax structures. However, while corporate income tax rate reductions (to a permanent flat 21%) were made permanent, the vast majority of individual, pass-through, and estate provisions were subject to statutory sunset clauses under congressional reconciliation rules.
At midnight on December 31, 2025, those temporary rules expire. Beginning January 1, 2026, individual marginal rates snap back to pre-2018 levels, vital pass-through deductions disappear, and unified estate exemptions fall by more than half. Passive filers will face severe tax drag; proactive enterprises must begin structural adjustments immediately.
1. The 39.6% Marginal Individual Bracket Snapback
Under current law, the top federal marginal income tax rate sits at 37.0% for high earners. Post-sunset, the top bracket immediately reverts to 39.6%. When combined with the 3.8% Net Investment Income Tax (NIIT) and state income taxes in high-SALT jurisdictions (such as California's 13.3% or New York's 10.9%), the total marginal tax rate on top-tier earners will easily surpass 54%.
Accelerate taxable income, harvest recognized capital gains, and complete multi-tier Roth IRA conversions during the 2024–2025 tax windows to lock in the 37% cap before the 39.6% reversion takes effect.
2. Complete Expiration of Section 199A (20% QBI Deduction)
For millions of small and mid-sized businesses structured as S-Corporations, Partnerships, and Sole Proprietorships, Section 199A has provided an unprecedented 20% deduction on Qualified Business Income (QBI). This deduction effectively reduced the top marginal rate on pass-through earnings from 37.0% to 29.6%.
When Section 199A vanishes on January 1, 2026, pass-through entities will see their effective federal tax rate climb by 10 percentage points overnight. In contrast, the corporate C-Corporation tax rate remains firmly anchored at 21.0%.
- C-Corp vs. S-Corp Reclassification Modeling: Businesses with substantial retained earnings must evaluate Form 8832 entity classification elections to take advantage of the 21% flat corporate rate.
- Reasonable Compensation Audits: S-Corp shareholder-employees must re-calibrate their W-2 salary versus dividend distributions to optimize FICA and income tax burdens.
3. Lifetime Estate and Gift Tax Exemption Halving
The unified lifetime federal estate and gift tax basic exclusion amount—currently standing at approximately $13.61 million per individual ($27.22 million for a married couple filing jointly)—will plummet to roughly $7 million per individual (adjusted for inflation) upon sunset.
Any wealth transfer above this compressed threshold is subject to a 40% federal transfer tax. Crucially, the IRS issued Treasury Decision 9884 (the "anti-clawback" regulations), confirming that gifts made under the higher exemption limits prior to 2026 will not be clawed back into the estate if the exclusion later decreases.
4. Strategic Wealth Preservation Roadmap
High-net-worth families should consult with their fiduciary advisors on implementing Spousal Lifetime Access Trusts (SLATs), Irrevocable Life Insurance Trusts (ILITs), and Grantor Retained Annuity Trusts (GRATs) to lock in existing exemption levels while assets can still be transferred gift-tax-free.