Updated July 29, 2026. Quick answer: No, and this is not an inference. The single occurrence of the phrase “lock-up period” in the entire Code of Federal Regulations is in a tax regulation, and it holds that an underwriting-agreement lock-up does not impose a substantial risk of forfeiture. Since section 83 taxes at the earlier of transferable or no-longer-forfeitable, a restriction that creates neither does not move the date.
The regulation, quoted
The only place the phrase “lock-up period” appears in the entire Code of Federal Regulations is a tax regulation, and it says the lock-up does not defer anything. Treas. Reg. §1.83-3(c)(4), Example 6: “Pursuant to an underwriting agreement entered into in connection with the initial public offering, Q agrees not to sell, otherwise dispose of, or hedge any Y common stock from August 1 through February 1 of 2014 (‘the lock-up period’) … The underwriting agreement does not impose a substantial risk of forfeiture on the Y shares acquired by Q because the provisions of the agreement do not condition Q’s rights in the shares upon anyone’s future performance (or refraining from performance) of substantial services or on the occurrence of a condition related to the purpose of the transfer of shares to Q.”
Read it against the test. IRC §83(a) includes the value in income for the first taxable year in which the rights are either transferable or not subject to a substantial risk of forfeiture. Treas. Reg. §1.83-3(c)(1) makes that risk turn on a condition tied to future performance of substantial services or to a condition related to the purpose of the transfer. Example 6 walks a lock-up through both limbs and finds neither. The lock-up stops you selling; it does not put the shares at risk of being taken back, and only the second thing moves the tax date.
Note the number in the example, too. The illustrated lock-up runs August 1 to February 1 — six months, not 180 days. Even the government’s own worked example is not the conventional figure, because no rule sets one.
Why double-trigger RSUs exist, corrected
The common explanation is that an IPO is not on the IRC §409A(a)(2)(A) list of permitted payment events, so the structure is built to fit the list. That is backwards. The operative provision is Treas. Reg. §1.409A-1(b)(4)(i), the short-term deferral rule, and its opening words are “A deferral of compensation does not occur under a plan with respect to any payment … that is not a deferred payment, provided that the service provider actually or constructively receives such payment on or before the last day of the applicable 2½ month period.” If the payment lands inside that window it is not nonqualified deferred compensation at all — §409A never attaches, so its list is never reached.
And here is the clause that kills a badly drafted award. Subparagraph (D) defines a deferred payment as one made “on or after any date, or upon or after the occurrence of any event, that will or may occur later than the end of the applicable 2½ month period … regardless of whether an amount is actually paid as a result of the occurrence of such a payment date or event during the applicable 2½ month period.” The test is on the plan’s terms, not on what happened. An award that says it settles on release of the lock-up, or in the next open trading window, is a deferred payment and loses the exclusion even if the shares are in fact delivered the following week.
Failing §409A carries, under §409A(a)(1)(B), an additional tax equal to 20 percent of the compensation required to be included, plus interest — which is why the drafting detail is worth more attention than the vesting headline.
The practical shape of it
Income is recognised when the award settles, the shares usually cannot be sold until the lock-up lifts, and the cash for the tax therefore has to come from somewhere other than those shares. Employers commonly withhold shares at a flat supplemental rate that may sit below your actual marginal rate; the gap is yours to fund, on the ordinary schedule, whatever the stock does in between.
And do not assume being an officer changes this. IRC §83(c)(3) is keyed to a fact, not a title — it applies “so long as the sale of property at a profit could subject a person to suit under section 16(b)” — and Treas. Reg. §1.83-3(j)(1) runs it only “until the earlier of (i) the expiration of such six-month period, or (ii) the first day on which the sale of such property at a profit will not subject the person to suit.” Where the acquisition was exempt under Rule 16b-3, no exposure arises and nothing is deferred. Example 6 settles it: Q is an officer of Y, and the example concludes “neither section 83(c)(3) nor the imposition of the lock-up period by the underwriting agreement precludes taxation under section 83 when the shares resulting from exercise of the option are transferred to Q.”
What §16(b) does and does not reach is a separate question, and for most people the answer is that it does not reach them.
Run your own numbers. RSU withholding gap calculator — see whether the 22% default leaves you short.
Sources
26 CFR 1.83-3(c)(4) Example 6; IRC §83(a) and §83(c)(3); Treas. Reg. §1.83-3(c)(1), §1.83-3(e), §1.83-3(j)(1) and (j)(2) Example 4; 17 CFR 240.16b-3(d); Treas. Reg. §1.409A-1(b)(4)(i) including subparagraphs (A) through (D); IRC §409A(a)(1)(B). Read July 2026.
This states what the cited authority says. It is not tax, legal or investment advice. Lock-up terms, award agreements and plan documents vary, and both the securities and the tax analysis turn on facts about your role and holdings that no page can see.