The Internal Revenue Code, in Section 83(b), offers taxpayers receiving equity in exchange for work the option to pay taxes on their options before they vest. If qualified, a person can tell the IRS they prefer this alternative in a process called an 83(b) election. Paying taxes early with an 83(b) election can potentially reduce taxes significantly. If the shares go up in value, the taxes owed at vesting might be far greater than the taxes owed at the time of receipt.
new With the passage of the Tax Cuts and Jobs Act (TCJA) in 2017, Congress approved a new Section 83(i) that is intended to allow deferral of tax until RSU and stock option holders can sell shares to pay the tax bill. Whether companies will choose or be able to make this available to employees is not clear yet.