Has the Supreme Court ever ruled that the 16th Amendment is invalid or improperly ratified?

1. The historical dispute that produced the Sixteenth Amendment

The Sixteenth Amendment was adopted after the Court’s decision in Pollock v. Farmers’ Loan & Trust Co. , which held that certain income taxes were “direct” taxes requiring apportionment among the states; Congress and the states responded by adopting the Amendment so that an unapportioned federal income tax would be constitutional ^{[4] [5]}.

2. Early Supreme Court treatment: Brushaber and the Amendment’s practical effect

When the Court confronted federal income‑tax challenges in the 1910s, its rulings treated the Amendment as operative and as removing Pollock’s apportionment barrier; the Brushaber line of cases and subsequent precedent have long anchored the Court’s view that the Sixteenth Amendment permits unapportioned income taxation ^{[1] [5]}.

3. Modern confirmation: Moore and the Court’s recent tax jurisprudence

In Moore v. United States, the Supreme Court rejected taxpayer claims that novel statutory provisions created an unconstitutional, improperly apportioned direct tax — a ruling that, according to analysts and counsel filings, reaffirms the Court’s existing Sixteenth Amendment framework rather than declaring the Amendment invalid or improperly ratified ^{[3] [2]}.

4. The claim that the Amendment was improperly ratified — what the record shows

Available sources do not report any Supreme Court decision finding the Sixteenth Amendment improperly ratified. Contemporary Court opinions and scholarly synopses treat the Amendment as valid law and resolve disputes within that constitutional framework rather than by attacking the Amendment’s legitimacy ^{[2] [5]}.

5. Why litigants sometimes raise “invalid‑ratification” theories

Tax litigants and fringe lawsuits periodically press constitutional theories — for example, claiming that certain taxes are direct and must be apportioned or that the Amendment’s words impose limits beyond settled precedent — but the Supreme Court’s recent responses (and lower‑court practice) show the Justices addressing these as statutory or doctrinal questions, not as grounds to invalidate the Amendment itself ^{[6] [2]}.

6. Scholarly and practitioner views: continuity, not revolution

Tax scholars and advocates who urge limiting readings of the Sixteenth Amendment are treated skeptically in mainstream commentaries: analyses filed around Moore argued against importing new “realization” or other limiting requirements into the Amendment’s text and warned that an expansive ruling for petitioners would unsettle much of the tax code ^{[6] [3]}.

7. How the Court frames income‑tax challenges today

The Supreme Court’s recent syllabi and opinions emphasize precedent: Pollock was overruled by the Amendment’s adoption in practice, and the Court applies long‑standing doctrine to determine whether particular statutory taxes fall within Congress’s power under Article I and the Sixteenth Amendment ^{[2] [5]}.

8. Limits of the available reporting and remaining uncertainties

The sources provided summarize doctrinal outcomes and contemporary cases but do not include any Supreme Court opinion declaring the Amendment invalid or improperly ratified; if such a ruling existed it would be a major, widely reported break from over a century of precedent — not found in current reporting ^{[2] [1]}.

Bottom line: claims that the Supreme Court has ruled the Sixteenth Amendment invalid or improperly ratified are contradicted by the Court’s doctrinal record as summarized in the provided sources; the Court continues to adjudicate income‑tax disputes within the framework that the Amendment establishes rather than by disavowing its ratification ^{[1] [2]}.