> If my stock in my biotech startup goes thru the roof and i get taxed X, i could perhaps sell some stock to cover. You don't have to unless your company is pu

> If my stock in my biotech startup goes thru the roof and i get taxed X, i could perhaps sell some stock to cover. You don't have to unless your company is publicly traded (or has shares readily tradable in a secondary market), and your personal shares in the company are worth in excess of $1B. > More likely, though, I will get into an installment plan with the IRS since the gains are so massive its going to be tough to sell so much stock without a discount, to pay the IRS off. No, you don't have to do that. The law allows you to carry-forward your first payment over 5 years. That's different from a payment plan, because if the stock goes to 0 in year 3, you no longer owe anything. So, I'd argue you are reading it incorrectly. Tim Sweeny gets a fair bit wrong, and I'd highly recommend starting with the actual legislative text (available here: https://www.finance.senate.gov/chairmans-news/wyden-unveils-billionaires-income-tax https://www.finance.senate.gov/chairmans-news/wyden-unveils-...) to get more details on the law.