Rule 10b5‑1(c)(1) under the Securities Exchange Act of 1934 includes an affirmative defense to insider trading liability for persons who sell securities pursuant to trading plans that meet the rule’s requirements. Concerned about potential abuses of trading plans, the SEC has adopted several amendments to the rule that limit the availability of that affirmative defense, including a minimum 90-day “cooling-off” period between the adoption of a plan and the first trade under the plan. It has also adopted new disclosure requirements pertaining to an issuer’s insider trading policies and trading plans adopted by its insiders. The final rule took effect on February 27, 2023. Most issuers will be required to comply with the amended requirements in the first filing that covers their first full fiscal period that begins on or after April 1, 2023. Smaller reporting companies will have until the first filing that covers their first full fiscal period that begins on or after October 1, 2023. This article discusses the final rule amendments and how they differ from the SEC’s original proposal, with commentary from Jonathan Hecht, partner at Goodwin Procter LLP and former assistant chief counsel and acting co-chief counsel in the SEC Division of Enforcement. See our two-part series “The Best-Laid Plans: Preventing Rule 10b5‑1 Plans from Going Awry”: Part One (Jun. 6, 2014); and Part Two (Jun. 13, 2014).