Single Trigger vs. Double Trigger Vesting for Founders

By Phillip Crowley, crowleylawllc.com
Summary for Founders: Acceleration controls whether unvested equity vests at closing or stays tied to continued service after the sale Acceleration lives in the equity plan, your award agreement and sometimes your employment or severance agreement Integration changes can decide the outcome, especially when the second trigger is tied to termination without Cause or for Good Reason Before you rely on acceleration language, confirm whether the clause is automatic or subject to board discretion If a buyer is asking about retention or your board is circulating draft deal documents, vesting acceleration is now an economic term, not background language 

This article explains how single-trigger and double-trigger acceleration work in a change of control, then points you to the definitions that drive the result and the document worth checking before you sign.

What Acceleration Is Actually Solving
Vesting was designed for a company that keeps operating under the same leadership and the same job expectations. A sale changes that and it can leave founders and executives exposed to losing unvested equity if integration reduces their role or ends employment. Acceleration is the mechanism that addresses that gap by tying vesting to a change of control alone or to a change of control plus a qualifying post-close employment event.

Single-Trigger vs. Double-Trigger in Deal Terms

Single-Trigger Acceleration
Single-trigger acceleration means the closing can be enough on its own, assuming the transaction fits the definition of “change of control” in your documents. The common trap is that the clause may apply only to certain awards or it may be written as board discretion. You should confirm which grants are covered, how much accelerates and whether acceleration is automatic.

Double-Trigger Acceleration
Double-trigger acceleration requires the deal to close and a qualifying employment event to happen after closing, usually tied to termination without Cause or for Good Reason. In practice, the second trigger often turns on integration: if your role stays intact, vesting usually keeps running on schedule. You should confirm what counts as the second trigger and the post-close time window for it to occur.

The Definitions That Decide Whether Acceleration Happens

Change of Control: Acceleration depends on whether the actual deal fits the plan’s definition, which may treat mergers, stock sales, and asset sales differently. Always map the transaction to the defined term before assuming acceleration applies.

Cause: In double-trigger setups, a termination for Cause usually blocks acceleration because it prevents the second trigger from being met. If Cause is drafted broadly, it can also become leverage during post-close integration disputes.

Good Reason: This is often where acceleration becomes workable, since it focuses on what changes after closing, like title, reporting lines, and core duties. Notice and cure requirements can still defeat a claim if you miss the required steps or deadlines.

A Short Founder Document Check Before the Term Sheet Hardens

Build a quick list of your grants, then mark what remains unvested as of the likely closing date
Open each award agreement and locate the acceleration provision for that specific grant
Check whether the clause is written as mandatory language or a board decision
Take the proposed transaction structure and compare it to the definition of “Change of Control” that governs your award
Confirm whether options and restricted stock units ("RSUs") follow the same trigger logic or are split by award type
Read the Good Reason and Cause definitions, as the buyer will use them after closing, then note any notice or cure steps that could block a claim If documents conflict, find the priority clause, so you know whether the plan, award agreement or employment terms win

FAQs

hat Counts As the ‘Second Trigger’ in Double-Trigger Clauses? The second trigger is usually a qualifying employment event after the deal closes, most often an involuntary termination without Cause or a resignation for Good Reason. Whether it applies depends on how those terms are defined and whether the event occurs within the post-close window set in your documents.

Where Is Acceleration Usually Defined and Which Document Controls? Acceleration is typically addressed in the equity plan and the individual award agreement, and sometimes in an employment or severance agreement. When terms conflict, the controlling document is often the one that governs the specific award, though many plans include a priority rule that overrides other agreements, so you need to check the hierarchy language.

Can Post-Close Role Changes Qualify as Good Reason? They can, but only if the definition of Good Reason treats the change as material. Reductions in responsibility, reporting level or authority may qualify, but notice and cure requirements can block a claim even when the role change is real, so timing and process matter as much as substance.

This is an adapted version of an article that appeared on our website. For full details, read the complete version here: https://www.crowleylawllc.com/single-vs-double-trigger-vesting-acceleration/.

​Crowley Law LLC is a boutique law firm providing full-service legal representation to emerging life sciences and other technology companies, supporting founders from early formation through growth and market entry. Call us today at 908-738-9398 to speak to our lawyers.