Income Tax Rates 2026 Bracket Changes: TCJA Expires, 39.6% Returns & Planning Window

The Tax Cuts and Jobs Act (TCJA) of 2017 lowered income tax rates across all brackets — most visibly reducing the top rate from 39.6% to 37% and restructuring the bracket thresholds. All individual income tax rate changes under TCJA expire after December 31, 2026, reverting to pre-TCJA law. For high-income taxpayers, the 2026 planning window — the last year at current rates — is one of the most significant tax planning opportunities in a decade. This guide explains what happens to each bracket, how the changes affect different income levels, and what actions to consider before the window closes.

Year-by-Year Action Plan: 2026 Tax Planning Checklist

With the December 31, 2026 deadline approaching, here are the key actions to consider in priority order:

High Priority (Do Before December 31, 2026)

Roth conversion: convert traditional IRA/401(k) funds to Roth, filling up the current 24% bracket (or 32%/35% if the math works). The tax-free growth benefit compounds for decades. Calculate the break-even — typically 5–10 years for moderate conversions. Harvest long-term capital gains: if you have unrealised long-term gains and are in the 0% or 15% LTCG bracket, consider realising gains before year-end 2026 — post-sunset, the threshold at which 0% applies may be similar but the 15%→20% crossover point shifts down. ISO exercise timing: if you have ISOs with large unrealised spreads, exercise in 2026 to benefit from the higher AMT exemption.

Medium Priority (Plan Now, Execute in 2026)

Business income acceleration: if you run a pass-through business, accelerate billing and collections to 2026 — defer deductible expenses into 2027 when deductions are worth more (higher rates). S-corp salary planning: in an S-corp, the ratio of salary to distributions affects SE tax but not income tax. In 2026 at lower rates, slightly higher salary (within reasonable bounds) may make more sense than aggressively minimising it. Estate planning: the estate tax exemption also expires in 2026 — see the separate estate tax guide. Complete large gifts before December 31, 2026.

Lower Priority (Monitor Legislation)

If Congress passes TCJA extension before your planned transactions: many of the above strategies become less urgent. Monitor Congressional developments through late 2026. The most likely scenario is at least partial extension — which provisions survive will determine the optimal strategy. Keep flexibility where possible.