What section 83 says, and what its regulation adds. Paragraph (c)(1) of the statute is the service condition and nothing more. The regulation goes further: 1.83-3(c)(1) extends the test to a condition on refraining from performing substantial services and to a condition related to a purpose of the transfer, and it attaches two limits worth knowing. Property is not subject to a substantial risk of forfeiture where the facts at the time of transfer show the forfeiture condition is unlikely to be enforced, and it is not at risk to the extent the employer must pay fair market value for part of the property when it comes back. The statute has two further parts people skip. Paragraph (c)(2) defines transferability in terms of the same idea: rights in property are transferable only if a transferee's rights would not themselves be subject to a substantial risk of forfeiture. That circularity is deliberate, and it closes the obvious workaround of selling the shares while the forfeiture condition still binds. Paragraph (c)(3) adds a narrow rule for insiders: so long as selling at a profit could expose the person to suit under section 16(b) of the Securities Exchange Act of 1934, the rights are both subject to a substantial risk of forfeiture and not transferable.
The 409A definition covers much the same ground from a different angle. The regulation's own words are that compensation is subject to a substantial risk of forfeiture "if entitlement to the amount is conditioned on the performance of substantial future services by any person or the occurrence of a condition related to a purpose of the compensation, and the possibility of forfeiture is substantial." It then tells you what a purpose-related condition means: it must relate to the service provider's performance for the employer or to the employer's business activities or organizational goals, and the examples given are the attainment of a prescribed level of earnings or equity value, or the completion of an initial public offering. Separately, and with no counterpart in the section 83 regulation, it provides that where entitlement turns on the service provider's involuntary separation from service without cause, the right is subject to a substantial risk of forfeiture if the possibility of forfeiture is substantial. A severance arrangement can therefore carry a risk of forfeiture even though no one is being asked to keep working.
Two things the 409A definition rules out, and the first is where the two regulations part company. A covenant not to compete does not create a risk of forfeiture for 409A purposes: "An amount is not subject to a substantial risk of forfeiture merely because the right to the amount is conditioned, directly or indirectly, upon the refraining from the performance of services." The section 83 regulation is softer. An enforceable requirement that the property be returned if the employee accepts a job with a competing firm "will not ordinarily be considered to result in a substantial risk of forfeiture unless the particular facts and circumstances indicate to the contrary", and the regulation lists what those facts are: the employee's age, the availability of alternative employment and the likelihood of obtaining it, the degree of skill possessed, the employee's health, and whether the employer has a practice of enforcing such covenants. A non-compete is a weak reed under section 83 and no reed at all under 409A. Second, adding a forfeiture condition after the legally binding right to the compensation has already arisen is disregarded, and so is extending the period an existing condition runs for, subject to one carve-out for certain transaction-based compensation tied to a change in control event. Deferral by retrofitted strings is not available.
The salary-deferral limit. The regulation also provides that an amount will not be treated as subject to a substantial risk of forfeiture beyond the date the recipient could otherwise have elected to receive it, unless the present value of the at-risk amount, ignoring the risk itself, is materially greater than the present value of what they could have taken instead. Its own illustration is blunt: deferring salary generally cannot be made subject to a substantial risk of forfeiture, because the employee could simply have taken the salary. But where a bonus plan offers a choice between cash and restricted stock units worth materially more that will be forfeited without continued service, the units generally do carry a real risk of forfeiture.
"Substantial" is a factual question, and ownership makes it a harder one. The regulation directs that where the person receiving the compensation owns a significant amount of the employer's equity, measured with section 318 attribution for a corporation, all the facts and circumstances are weighed in deciding whether the employer would really enforce the forfeiture, including that person's relationship to the other equity holders and the extent of their control. A founder who writes her own vesting schedule and could rewrite it tomorrow has a weaker case than an employee at arm's length. A stock right gets its own rule: an option stops being subject to a substantial risk of forfeiture at the earlier of the first date it may be exercised for substantially vested stock and the first date it carries no qualifying forfeiture condition, so an immediately exercisable option is not protected by the fact that it lapses on departure.