Updated July 29, 2026. Quick answer: Any modification to the amount, price, or timing of purchases or sales under a 10b5-1 plan is treated as a termination of that plan and the adoption of a new one. A fresh cooling-off period starts from that date. Rule 10b5-1(c)(1)(iv) names substituting or removing the executing broker as an example, where the substitution changes the price or the date on which trades execute.
The provision, and why it is broader than it looks
Rule 10b5-1(c)(1)(iv) provides that any modification or change to the amount, price, or timing of the purchase or sale of the underlying securities “is a termination of such contract, instruction, or written plan, and the adoption of a new contract, instruction, or written plan.” It then supplies the example most likely to catch someone out: “the substitution or removal of a broker that is executing trades pursuant to a Rule 10b5-1 arrangement … that changes the price or date on which purchases or sales are to be executed, is a termination of such plan and the adoption of a new plan.”
The trap is administrative rather than strategic. Moving an account, consolidating brokers, or a broker’s own operational change to execution timing can each alter the price or date and therefore restart the clock — for a director or Section 16 officer, that means waiting again for the later of ninety days after the modification, or two business days after the Form 10-Q or 10-K disclosing results for the completed fiscal quarter in which the modification was made, capped at 120 days.
Re-adoption also re-runs the other conditions. If the modification is an adoption of a new plan, then the plan-level requirements apply again as of that date — including, for a director or Section 16 officer, the written certification in the plan that they are not aware of material nonpublic information and are acting in good faith. A modification made while holding material nonpublic information is not a modification of a protected plan; it is the adoption of an unprotected one.
Plans adopted before February 27, 2023
The amendments took effect on February 27, 2023. The SEC’s adopting release states that the amendments to Rule 10b5-1(c)(1) “would not affect the affirmative defense available under an existing Rule 10b5-1 plan that was entered into prior to the revised rule’s effective date, except to the extent that such a plan is modified or changed” in the manner described above — in which case the modification is equivalent to adopting a new arrangement and the amended rule governs it in full.
The consequence for a long-standing plan. A plan running since before February 2023 keeps the older defence untouched. One administrative change — a broker substitution that shifts execution dates — converts it into a plan adopted today, subject to every current condition including the cooling-off period, the certification, the overlapping-plan limit and the single-trade limit. Grandfathering is durable and it is fragile at the same time.
What is not a modification
The rule keys on amount, price, and timing. A change that does not touch any of the three is not converted into a termination and re-adoption by this provision. The adopting release separately discusses an ongoing good-faith requirement in (c)(1)(ii)(A); what conduct breaches it is not characterised here, because that discussion was not read in the primary-source pass behind this page.
Sources
17 C.F.R. §240.10b5-1(c)(1)(ii)(B), (C), (D) and (E), and §240.10b5-1(c)(1)(iv), which defines “officer” by cross-reference to Rule 16a-1(f); Insider Trading Arrangements and Related Disclosures, Release Nos. 33-11138 and 34-96492, 87 Fed. Reg. 80362 (Dec. 29, 2022). All read July 2026. Rule 16a-1(f) itself was not pulled and its text is not quoted here.
This states what the cited authority says. It is not tax or legal advice. Constructive-sale analysis, partnership nonrecognition and insider-trading defences all turn on transaction documents and facts that no page can see, and the instruments described here are executed under contracts whose terms vary by provider.