When did the US switch to first-to-file?

The Leahy-Smith America Invents Act (AIA) switched the US patent system from first-to-invent to first-to-file effective March 16, 2013, for applications with at least one claim that has an effective filing date on or after that date.

Does the one-year grace period still exist under first-to-file?

Yes, but in a narrower form. Under 35 U.S.C. § 102(b)(1), an inventor's own disclosure made within one year before the filing date is not prior art. However, third-party disclosures made after your own disclosure but before your filing date can still bar your patent in some circumstances. The safest approach is to file before any public disclosure.

What is the difference between first-to-file and first-to-invent?

Under the old first-to-invent system, the inventor who could prove the earliest date of invention had priority. Under first-to-file (post-AIA), priority goes to the first person to file a patent application, regardless of when they actually conceived the invention. This makes the filing date the critical date.

Can I still prove I invented something first to win a patent dispute?

Under first-to-file, prior invention date is generally irrelevant to priority. The AIA replaced interference proceedings (which determined who invented first) with derivation proceedings, which only apply to the narrow case where someone derived the invention from the true inventor without authorization.

Patent Law · AIA 2013

First-to-File: What the US patent race actually means

On March 16, 2013, the US switched from first-to-invent to first-to-file. The race to the patent office became the only race that counts. Here's exactly what changed — and what didn't.

Key takeaways

→Priority now goes to the first inventor to file, not the first to invent.
→The filing date — not the invention date — determines what counts as prior art.
→A one-year grace period still exists, but only for the inventor's own prior disclosures.
→Third-party disclosures before your filing date can bar your patent, even after your own disclosure.
→File before you publish, demo, or sell — not after.

The Law

What changed on March 16, 2013

The Leahy-Smith America Invents Act (AIA) — signed into law September 16, 2011 — rewrote the core of US patent priority. For any application with at least one claim having an effective filing date on or after March 16, 2013, the US joined the rest of the world in a pure first-to-file system.

Under the pre-AIA system, two inventors could file for the same invention and the one who could prove an earlier date of conception (not filing) would prevail. That dispute was resolved through an inter partes proceeding called an interference. Interferences were expensive, slow, and uniquely American.

Under first-to-file, the question of who invented first is nearly irrelevant to who gets the patent. The AIA abolished interference proceedings. In their place are derivation proceedings — a much narrower process that only applies when someone files a patent claiming an invention that was derived (stolen) from the true inventor without authorization.

The Grace Period

The one-year window — and its limits

The AIA preserved a one-year grace period, but narrowed it. Under 35 U.S.C. § 102(b)(1), a disclosure made within one year before the filing date is not prior art if that disclosure was made by the inventor, or by someone who obtained the invention from the inventor.

This means: if you publish a paper about your invention, you have one year to file before that paper becomes prior art against you. That much is the same as before.

The trap: If a third party independently publishes the same invention after your disclosure but before your filing date, you are not protected against that third-party disclosure in all circumstances. The safe rule is: file before you disclose publicly.

The practical consequence: the old strategy of "disclose it, lock in the date, then take a year to polish the application" is riskier now. A competitor who independently arrives at the same idea and files before you can now win — even if you publicly disclosed first, under certain prior-art frameworks introduced by the AIA.

Prior Art

Your filing date is now the critical date

Under the old system, the "critical date" for prior art was typically tied to the inventor's date of invention. Under first-to-file, the critical date is the effective filing date of the application.

This has a practical consequence: anything published, sold, or publicly disclosed anywhere in the world before your filing date is potentially prior art against you, regardless of when you conceived the invention. There is no longer a mechanism to "swear behind" a reference by proving an earlier invention date.

The effective filing date is usually the date of the actual application. But if you filed a provisional patent applicationfirst, a non-provisional filed within 12 months can claim the provisional's filing date as its effective date — which is one of the strongest reasons to file a provisional early.

Practical Rules

What first-to-file means for you

File before you disclose

Presenting at a conference, posting a video, publishing a paper, or showing a demo publicly all start the one-year clock. Once it expires, your own disclosure bars your patent. Filing a provisional first costs less and locks in your date.

File before you sell or offer to sell

An offer for sale — even a private one — can count as a disclosure event under § 102(a)(1). The one-year grace period applies, but it's a tight window. Negotiations with manufacturers or licensees can create risk.

Speed matters more than perfection

A provisional filed today is worth more than a polished non-provisional filed in six months. The provisional locks in your priority date for 12 months. You can keep developing while the clock runs.

Don't rely on your invention date

You can no longer 'swear behind' a prior art reference by proving you invented before it was published. If it was published before your filing date, it's prior art. There is no workaround.

FAQ

Can I still use an inventor's notebook to prove invention date?

Under first-to-file, an inventor's notebook no longer establishes priority over a competitor who filed first. It may still be relevant for derivation proceedings (proving an invention was stolen), and is useful for documenting inventorship, but it does not help you win a race against a competing filer.

What happened to interference proceedings?

They were abolished for AIA applications. The Patent Trial and Appeal Board (PTAB) now handles derivation proceedings instead, which are limited to cases where someone filed a patent derived from the true inventor without authorization. These are rare compared to old interferences.

Does first-to-file apply to all pending patent applications?

First-to-file applies to applications where at least one claim has an effective filing date on or after March 16, 2013. Applications filed entirely before that date, or continuation applications claiming priority to pre-AIA applications for all claims, are governed by the old first-to-invent rules.

Is the US truly 'harmonized' with the rest of the world now?

Closer, but not fully. The US grace period (§ 102(b)(1)) still offers inventor-friendly protection that most other jurisdictions do not — most require absolute novelty with no grace period. The US system is first-to-file but not absolute-novelty.