TL;DR

Your deadline is the earlier of: (a) a Notice of Allowance, or (b) the later of 6 months post-publication or the first Office Action date. Enter your dates below to check instantly.

The Statutory Rule

Under 35 U.S.C. § 122(e), a Third-Party Preissuance Submission must be filed before the earlier of:

The date a Notice of Allowance (NOA) is issued; or
The later of:
- 6 months after the application is published; or
- The date of the first rejection of any claim

The "Brittle" Window Explained

The Notice of Allowance is a hard stop — it can arrive at any time with no warning. If an NOA is issued, the window closes immediately. This is why practitioners call the window "brittle." Do not wait.

How the window plays out — five real scenarios

Publication is the only fixed point. Everything else — how long before publication, when the first rejection lands, when an NOA arrives — varies case by case. Match your application against the row that fits.

6 months after publication

1 · First rejection arrives within 6 months. No change — the window still runs to the 6-month mark, because 6 months is the later date.

1st OA closes

2 · First rejection arrives after 6 months. The window stays open past the 6-month mark and closes on the exact day the first Office Action mails — not a fixed offset after it. This is the case people most often get wrong.

1st OA · closes

3 · Still pending, no rejection yet. Silence is not a deadline. Past the 6-month mark with no first Office Action, the window simply stays open — until an OA or NOA lands. Monitor the file wrapper.

today · still open

4 · Notice of Allowance issues. A hard stop that overrides everything — it can land anywhere on the timeline, even before the 6-month mark, with no warning. This is why the window is called "brittle."

NOA · hard stop

5 · PCT or priority-claiming application. Publication happens early (~18 months from the priority date), but examination starts late — so the first OA, and with it the close of the window, often lands years past the 6-month mark. Why the PCT window is so much bigger →

national phase entry 1st OA · closes

publication — the fixed anchor the 6-month floor (same in every case) variable / unbounded time window closes 6-month mark

The Calculator

§ 122(e) Deadline Calculator

Has a Notice of Allowance (NOA) been issued? — If yes, the window is closed.

Publication Date Required

Found on the front page of the published application (e.g., US 2024/0123456).

First Office Action Date (Optional)

The mailing date on the first Office Action on the merits. Leave blank if none has issued.

This calculator provides an estimate. Always verify deadlines independently and consult a qualified patent practitioner for time-sensitive filings.

Claiming an earlier priority date?

For applications claiming priority to a provisional, foreign, or PCT filing, the publication clock runs from the earlier priority date while examination runs from the actual US filing date. The result: the first Office Action usually lands well after the 6-month mark, and the "later of" clause — not the 6-month rule — controls the deadline. See Strategic Timing for why this window is often years long.

How to Find the Relevant Dates

Publication Date

Appears on the face of the published patent application. Also searchable in Google Patents and USPTO Patent Center by application number.

First Office Action Date

In USPTO Patent Center ↗, under "Documents & Transactions," look for the first document labeled "Non-Final Rejection." The mailing date is printed on its cover.

Notice of Allowance

Also in the Image File Wrapper. If the most recent action is an NOA, the window is closed.

Edge Cases & Nuances

Situation	Effect on Window
Published, no OA yet, within 6 months	Window open. Deadline = pub date + 6 months (may extend — see next rows).
Published, no OA yet, more than 6 months elapsed	Window still open. It closes on the day the first OA (or an NOA) mails.
First OA issued more than 6 months after publication	Window ran until the OA date, then closed.
First OA issued within 6 months of publication	No extension. Deadline remains pub + 6 months.
Application claims earlier priority (provisional, foreign, PCT)	Publication comes early relative to examination — the first-OA prong usually controls. See Strategic Timing.
NOA issued at any point	Window immediately closed.
Application abandoned	Cannot file.
Continuation or divisional application	Each application has its own independent window.

Statutory Deadline Calculator