What specific tax proposals has Zohran Mamdani proposed and when were they introduced?

Executive Summary — Direct answer up front: Zohran Mamdani has publicly backed a package of tax increases aimed at wealthy individuals and large corporations, most prominently a 2 percentage‑point New York City income tax surcharge on individuals earning more than $1 million and an increase in the state top corporate tax rate to about 11.5 percent. These measures were advanced publicly during the 2024–2025 campaign and immediately after the November 4, 2025 mayoral victory, with reporting and fiscal critiques published in late October through early November 2025 ^{[1] [2] [3] [4]}. The chief factual disputes concern the timing of formal introduction (campaign pitch vs. legislative filing), the magnitude of projected revenue, and whether Albany has the legal will to enact the changes ^{[2] [4] [1]}.

1. The headline tax proposals — what he’s proposed and the numbers reporters quote: Mamdani’s most prominent, repeatedly reported proposals are a 2-point city income tax surcharge on earnings above $1 million, and raising the state’s top corporate tax rate from roughly 7.25% to about 11.5%. Advocates frame this as a combined plan to raise roughly $9 billion annually—about $4 billion from the millionaire surcharge and $5 billion from corporate rate increases—to fund free buses, universal child care, and other municipal programs ^{[1] [2] [3]}. Coverage from late October and early November 2025 consolidates those headline numbers while noting they were issued as part of Mamdani’s budget priorities and campaign promises, rather than as enacted legislation ^{[1] [4]}.

2. The accounting battle — why independent analysts push back on the $9 billion claim: Multiple fiscal critiques published in late October 2025 find the revenue math overstated. Analysts estimate the corporate tax increase would likely raise $2.6 billion to $3.8 billion, not the $5 billion claimed, and the millionaire surcharge would likely generate roughly $2.2 billion to $2.9 billion rather than $4 billion. Those downward revisions hinge on realistic taxpayer responses and base‑narrowing effects, which the campaign’s figures do not appear to fully model ^{[2] [1]}. The disagreement is not about whether the taxes target high earners and large firms—sources agree they do—but about how much revenue will actually materialize once avoidance, relocation, and statutory interactions are considered ^[2].

3. Timing and legal pathway — campaign promise versus statutory reality: Reporting through September–November 2025 shows Mamdani floated these proposals as campaign and budget plan items, not as bills that had already cleared Albany. A mayor cannot unilaterally impose state tax increases; implementation would require state legislative action and gubernatorial assent, and Governor Kathy Hochul publicly opposed raising statewide income taxes in the immediate coverage ^{[3] [4]}. Some state legislative leaders have at times signaled openness to taxing wealthier taxpayers, but the sources emphasize the political and legal hurdles that mean these remain policy proposals pending formal introduction and negotiation in 2026 ^{[3] [4]}.

4. Broader tax‑and‑policy record — other proposals and legislative history that matter: Beyond the millionaire surcharge and corporate hike, Mamdani’s record and earlier policy advocacy include proposals like worldwide combined reporting for large corporations (MEGA corporations act) and a billionaire mark‑to‑market tax, along with targeted credits such as a small business credit for hiring disabled workers and an inheritance tax idea. These items appear in his state Assembly tenure and prior platforms dating back to 2021–2022 and signal a longstanding emphasis on taxing extreme wealth and corporations to fund public programs ^{[5] [6] [7]}. Those earlier bills give context to the mayoral pitch: they are part of a coherent policy orientation rather than ad hoc proposals ^[5].

5. What remains uncertain and why it matters for voters and policymakers: Key uncertainties persist around exact statutory text, the dates bills were or will be formally filed, and independent scorekeeping of projected revenues. Sources diverge on the timing: some describe the tax ideas as campaign commitments made in late 2025; others document related legislative initiatives from Mamdani’s Assembly service years earlier ^{[8] [4] [5]}. The central takeaway is clear: the policy direction is explicit and recent, but the legal enactment and reliable revenue estimates are unresolved, meaning political negotiations in Albany and independent fiscal scoring will determine final outcomes ^{[2] [3]}.