Filing a Form 83(b) election is related to exercising stock options or receiving restricted stock, not to selling the stock. An 83(b) election allows you to pay taxes upfront on the fair market value of the shares when they are granted or when you exercise your options, rather than waiting for them to vest. If you believe the value of your stock will substantially increase over time, filing an 83(b) election can be beneficial because it allows you to pay taxes on the lower value at the time of exercise or grant, rather than on a higher value when the stock vests. You generally have 30 days from when you exercise your stock options or receive restricted stock to file the 83(b) election with the IRS. If you've already exercised your stock options or received restricted stock and the 30-day period has passed, you can't file the 83(b) election for those shares. It's important to remember that filing an 83(b) election comes with risks, such as paying taxes on stock that may ultimately decline in value or never vest. You should carefully consider your specific situation and consult a tax professional if you're unsure whether filing an 83(b) election is right for you.