When RSUs vest (the stock is delivered) the entire amount is ordinary income. Your employer must collect payroll taxes, or sell shares to pay it. Since you are taxed on the entire amount, you basis is the amount that is added to your W-2 which you are taxed on. If you retain the stock, any gains on the sale will be short term if you hold the stock one year or less, and long term if you hold it more than one year.
You definitely don't want to use $0 as your cost basis. a $1 gain or loss on the sale of RSUs on the day of vesting is reasonable. Use the $3,999 as your cost basis.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
