US Patent Litigation: District Courts, the ITC and PTAB

US patent litigation is distinctive among the major jurisdictions, and understanding its shape early helps a rights holder or an accused infringer choose the right forum and set realistic expectations. There is no single "patent court" of first instance for infringement; instead, several routes run in parallel, each with its own remedies, procedure and cost profile. This guide sits under the US patents pillar and frames the main options at a high level.

The district court route

Infringement of a US patent is heard in the federal district courts, which hear patent infringement suits to the exclusion of the state courts. A patent owner sues for infringement; the defendant typically denies infringement and, very often, counters that the patent is invalid or unenforceable. A feature that surprises parties from other jurisdictions is the availability of a jury trial on many issues, including infringement and factual questions bearing on validity, with the judge deciding questions of claim construction (the meaning of the patent's claims) at a dedicated stage frequently called a Markman hearing. Certain districts have historically attracted a large share of patent filings, and where a case can properly be brought is itself contested ground, so venue and forum strategy matter from the outset. Appeals from the district courts in patent cases go to a single specialist appellate court, the Court of Appeals for the Federal Circuit, which brings a degree of national consistency to patent law. Timeframes vary widely from district to district and case to case, so treat any single figure with caution and confirm the current position for your forum with the US federal courts or local counsel.

The ITC route

The US International Trade Commission offers a parallel path where the allegedly infringing goods are imported into the United States. A section 337 investigation at the ITC is not a claim for money; its principal remedy is an exclusion order, which is directed to US Customs and Border Protection, which enforces it by barring infringing imports at the border, and the ITC can also issue cease and desist orders. The ITC is known for a comparatively fast, front-loaded procedure and for a requirement that the complainant show a domestic industry tied to the patent. Because the ITC cannot award damages, patent owners frequently run an ITC investigation and a district court case together: the ITC pursues an import ban while the court pursues compensation. For a broader view of how import bans and multi-forum strategy fit international enforcement, see cross-border enforcement.

Challenging validity at the PTAB

Validity can be attacked inside the courts, but it can also be challenged separately before the Patent Trial and Appeal Board at the USPTO. The most used mechanism is inter partes review (IPR), an administrative proceeding in which a challenger argues that the patent should not have granted over earlier patents and printed publications. IPR is confined to novelty and obviousness grounds based on that prior art, so other validity attacks, such as subject-matter eligibility, indefiniteness or lack of written description, remain for the courts rather than the Board. PTAB proceedings are often quicker and less costly than a full court trial on validity, and an accused infringer sued in district court will commonly file an IPR petition and ask the court to pause its case while the Board decides. There are timing limits on when a petition can be filed after being served with an infringement complaint, and the interaction between a stay, the district court schedule and the ITC can be intricate, so confirm the current deadlines and estoppel consequences with the USPTO or a qualified professional before relying on this route.

Injunctions, juries and cost

Since the Supreme Court's decision in eBay v MercExchange, a US court does not grant a permanent injunction automatically on a finding of infringement. The patent owner must satisfy the traditional equitable test (irreparable harm, that monetary damages are inadequate to compensate, the balance of hardships and the public interest), which has made injunctions harder to obtain, particularly for parties that do not themselves practise the invention. This is a meaningful contrast with jurisdictions where an injunction follows more readily, and it shapes settlement dynamics. Combined with jury trials, extensive discovery and the front-loaded nature of ITC work, US patent litigation is widely regarded as among the most expensive in the world. Official fees apply at the USPTO and the courts; confirm the current amount with the USPTO and the US federal courts or local counsel, and budget for professional costs well beyond any official fee.

A note on this guide

IPEnvoy is not a law firm and does not provide legal advice; this is general information only. US patent disputes turn on the specific patent, the products, the forum and the current rules, so confirm the current position with the USPTO and the US federal courts and a qualified local IP professional before acting. Where a matter looks likely to become contentious, IPEnvoy can introduce you to vetted US litigation counsel with experience across the district courts, the ITC and PTAB, so the strategy is set by people who run these cases day to day.