Income Tax Plannerv2

What questions does this answer?

A · Marginal sensitivity

How does my total tax burden change if my income is $10k higher or lower? The chart shows the full sweep so you can see cliffs, humps, and flat regions at a glance.

B · Sweet spots & danger zones

Where are the SS torpedo, IRMAA tier crossings, and NIIT threshold? The vertical reference lines and marginal rate curve (purple dashed) make them immediately visible.

C · True all-in effective rate

Federal + state + IRMAA combined, not just the marginal bracket. The white line on the Tax Rates view is the number that actually matters for planning.

D · Withholding guidance

Hover your expected income on the chart. The info panel below shows every component — rates and dollars — simultaneously at that income level.

How the income sweep works

The x-axis sweeps ordinary income from $0 to $1.1M in $10k steps. Ordinary income covers wages, IRA/401k withdrawals, pensions, and RMDs — anything taxed at regular rates. Social Security and capital gains are entered as fixed amounts that apply at every point across the sweep, letting you see how they interact with the income ramp. The top x-axis shows the total income (ordinary + SS + CG gain) at each corresponding point.

The chart

• Tax Rates view — federal effective (blue), state effective (orange), total effective (white), and federal marginal on ordinary income + CG (purple dashed).
• Tax Dollars view — stacked bars for Federal Ordinary, Federal CG, IRMAA, State Ordinary, and State CG. The teal line (right axis) is your MAGI — the figure used to determine next year's IRMAA tier.
• Info panel — hovering the chart shows all rates and dollar amounts for that income level simultaneously, regardless of which view is active.
• IRMAA tier lines — click any IRMAA entry in the legend (Tax Dollars view) to toggle its vertical reference line.
• Top axis — shows total income (ordinary + SS + CG) at each $100k ordinary income mark. When SS and CG are zero it matches the bottom axis.

Caveats & known simplifications

• IRMAA lookback: Medicare IRMAA uses your MAGI from two years prior. This tool applies it to current-year MAGI — convenient for planning but optimistic by about two years if you've recently had a high-income year.
• OBBBA provisions (senior deduction, elevated SALT cap) are modeled from best-available bill text as of mid-2025. All parameters (phase-out thresholds, caps, sunset year) are sourced from TAXData.OBBBA — update that block when IRS guidance is published. The $40k SALT cap automatically reverts to $10k for years after ${obbaSalt.sunsetYear}.
• Nebraska brackets are approximate based on the LB754 phase-down schedule; confirm with NE DOR for your specific year.
• SS provisional income thresholds ($32k/$44k MFJ, $25k/$34k Single) are intentionally not inflation-adjusted — that is current law, and the reason the SS torpedo worsens over time.
• NIIT threshold ($250k MFJ / $200k Single) is also not inflation-indexed — another orphan in the tax code, unchanged since 2013.
• Excluded: AMT, self-employment tax, CA SDI, qualified dividends (modeled as CG), muni bond interest, CA personal exemption credits.

Share button

The Share button encodes all current settings into the URL and copies it to your clipboard. Paste it into any browser — or save it as a bookmark — to restore the exact same configuration. Works from a local file (file://) as well as a web server.