Supreme Court Rule 37.3(a) gives an outside group exactly 7 days after a party’s brief is filed to submit its own brief backing that side. Applied to Apple Inc. v. Epic Games, Inc., that rule puts September 21, 2026 on the calendar as the deadline for any amicus brief supporting Apple, one week after Monday’s filing.
The rule is procedural, not predictive. It says nothing about who will file or what they will argue, only when a filing is due if someone chooses to make one. It applies the same way in every case the Court hears for oral argument, including this one over App Store rules that reach devices such as the iPhone 18 Pro and the iPhone Duo, both covered in Apple’s September announcements and unaffected by anything iOS 27 changes on Monday.
Key facts
| Item | Detail |
|---|---|
| Rule | Supreme Court Rule 37.3(a) |
| Deadline for amicus supporting Apple | 7 days after Apple’s brief, by September 21, 2026 |
| Deadline for amicus supporting Epic | 7 days after Epic’s brief, by November 20, 2026 |
| Deadline for amicus supporting neither party | Tied to the time allowed for Apple’s brief |
| Extensions | Rule 37.3(a) states none will be entertained |
What Rule 37.3 actually says
The rule’s own text states that an amicus brief “shall be submitted within 7 days after the brief for the party supported is filed, or if in support of neither party, within 7 days after the time allowed for filing the petitioner’s or appellant’s brief.” The Court has also written into the rule that “motions to extend the time for filing an amicus curiae brief will not be entertained,” a stricter line than the extension Apple itself was granted in July for its own opening brief.
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Two different amicus tracks in the same case
| Stage | Rule | What happened in this case |
|---|---|---|
| Certiorari stage | Rule 15, tied to the petition, not the merits | One brief filed June 3, 2026, before cert was granted |
| Merits stage | Rule 37.3, 7-day clock tied to each party’s brief | No filings yet; the earliest possible one follows Monday |
The one amicus brief already in the case, filed by the Computer & Communications Industry Association and other organizations on June 3, 2026, belongs to the first track. It was filed while the Court was still deciding whether to hear the case, under a different provision with no fixed relationship to Monday’s deadline. Nothing about it extends, shortens, or otherwise changes the 7-day window that opens once Apple’s brief on the merits is actually filed.
The word limit and the filing itself
Merits-stage amicus briefs are also shorter than the parties’ own filings. Rule 33.1 caps a petitioner’s or respondent’s principal brief at 13,000 words; an amicus brief in the same case is capped at 9,000 words under the Court’s current rules. A filing must also state whether it has the consent of the parties or needs the Court’s leave to be filed.
What the rule does not do
None of this compels anyone to file. Rule 37.3(a) sets a deadline if a brief is filed, not a requirement that one be. It also does not shorten the case’s own timeline. Epic’s response brief remains due November 13, 2026 regardless of what happens with amicus filings on either side, and no argument date exists on the docket yet. Nor does the rule say anything about what an amicus brief must argue; a filing that meets the September 21 deadline could support Apple’s reading of Question 1 narrowly, broadly, or on grounds Apple’s own brief does not raise, and the rule treats all three the same way procedurally.
What Apple has not said
- Whether it has been in contact with any organization about filing in support of its position.
- Any indication that additional amicus support is expected by September 21.
- A response to the sole amicus brief already filed in the case.
Today is Sunday, September 13, 2026. Apple’s brief is due tomorrow, and September 21 is the date to check the docket again for anything filed in support of it.
