In percent of US total tax revenue, how much is paid by billionaires?

1. Billionaires vs. the tax base — what the new research says

A major working paper, “How Much Tax Do U.S. Billionaires Pay? Evidence from Administrative Data,” finds that the ultra‑rich now face much lower overall effective tax rates than before and lower rates than many ordinary workers; Berkeley’s summary of the research emphasizes the decline in total effective tax rates for the 400 wealthiest Americans over recent years ^{[1] [2]}. The authors leverage administrative tax and financial records to calculate “true” tax burdens and conclude that the combination of wealth concentration, capital‑income treatment, and post‑2018 tax law changes pushed effective rates down for the ultra‑wealthy ^{[2] [1]}.

2. Why you won’t find a clean “percent of total revenue” number for billionaires

Government and public‑interest sources report tax shares by income groups (for example, USAFacts documents the top 5% paid roughly 61% of income tax in 2022), but they do not isolate “billionaires” as a distinct contributor to total federal receipts, nor do the academic studies convert billionaire tax payments into a share of overall federal revenue in one headline number (p1_s10; available sources do not mention a precise percent of total tax revenue paid by billionaires). Estimating that share requires choices — which taxes to count (individual income, payroll, corporate, estate), which population to call “billionaires,” and whether to include state/local collections — and the sources provided do not supply a single canonical estimate.

3. Magnitude context: top earners pay most income tax; billionaires are a sliver of taxpayers

Data show the top income fractiles are responsible for the lion’s share of income‑tax revenue: USAFacts reports the top 5% paid about $1.3 trillion or ~61% of income tax in 2022 ^[3]. By contrast, billionaires number only in the thousands nationally and are a tiny slice of tax units; academic and policy analyses repeatedly stress that a very small group concentrates a large share of wealth but not correspondingly large shares of tax payments relative to their income or wealth ^{[2] [4]}.

4. How researchers and advocates frame different claims

Advocacy groups, like Oxfam, highlight revenue potential from taxing billionaire wealth (for example estimating a modest 3% levy on fortunes over $1 billion would raise large sums from the richest ten) to argue billionaires underpay relative to societal needs ^[5]. Conversely, think‑tank and legal analyses of proposed wealth taxes (California ballot analyses, legal briefs) focus on implementation, behavioral responses (migration, tax planning) and constitutional issues that could reduce expected yields ^{[6] [7]}. Both perspectives use different assumptions about compliance, mobility, and what counts as “taxes,” so they reach different policy conclusions ^{[5] [6] [7]}.

5. Estimates and proposals: wealth taxes vs. income tax receipts

International and policy studies model wealth taxes as potential revenue sources: the Elcano Institute projects a small global minimum wealth tax on billionaires could add revenue on the order of 0.22% of global GDP in 2025 ^[8]. U.S. proposals — from ballot initiatives to congressional bills — envisage one‑time or ongoing taxes on billionaire net worth to raise tens or hundreds of billions for state or federal programs, but the Legislative Analysis Office and legal commentators warn revenue outcomes are uncertain because of avoidance and relocation ^{[6] [7] [9]}.

6. Competing data on effective tax rates — different methods, different answers

Different research efforts produce divergent effective‑tax‑rate estimates for the very wealthy because they measure different units (top 400 families, top 0.1%, billionaires), include different taxes (federal only vs. federal+state+corporate+estate), and use different imputations for unrealized gains. For example, analyses discussed by Equitable Growth and Tax Foundation cite effective tax rates ranging from single digits for the top few families to much higher combined rates for broader “super‑rich” groups when corporate and estate taxes are folded in — illustrating why headline numbers differ across sources ^{[10] [11]}.

7. Bottom line and reporting limitations

There is strong, repeatedly cited evidence that the ultra‑wealthy pay lower effective rates than many Americans and that concentrated wealth has grown; however, the sources provided do not produce a single, agreed percentage of total U.S. tax revenue paid specifically by “billionaires” ^{[1] [2] [3]}. Any precise percent would require new tabulations that define the group, select which taxes to include, and account for corporate/estate allocations — steps not present in the current reporting (available sources do not mention a precise percent of total tax revenue paid by billionaires).