What Happened
In 2012, Congress created a new way to challenge patent validity at the Patent Office itself, called Inter Partes Review or IPR. Instead of suing in federal court, you file a petition at the PTAB (Patent Trial and Appeal Board). If they take your case, you get a faster, cheaper shot at invalidating the patent.
Why It Matters
IPR has become a central tool in patent disputes. Here's how it works: You file a petition showing the patent is likely invalid based on prior art patents or publications. The PTAB decides whether to "institute" review—about 60-65% of petitions make it that far. If they do, you get about a year of proceedings, then a final decision. When the PTAB takes a case, they cancel at least some claims in over 80% of them.
Compare that to district court, where patents are presumed valid and you need clear and convincing evidence to invalidate. At the PTAB, it's just a "preponderance of the evidence" (more likely than not), and the judges are technically trained. For defendants, it's often a better bet.
But there are tradeoffs. You only get to challenge based on patents and publications—no evidence of prior use or sales. You're estopped from raising the same arguments later in court. And if you lose, the patent survives with a stronger presumption of validity.
What You Should Know
If you're sued for patent infringement, consider filing an IPR petition. You only have one year from when you're served, so move quickly. Even if the PTAB doesn't take your case, you might get a district court stay pending their decision.
If you're a patent owner, expect IPR challenges. Draft your patents with IPR in mind—multiple claim sets, varying scope, strong support in the specification. And consider whether to settle before institution; once the PTAB institutes, they control the proceedings.
IPR isn't perfect, but it's become an essential part of patent litigation strategy.