Restricted stock units (RSUs) are company shares granted to employees. RSUs that appear on Form W-2 indicate that shares have been delivered to you, which usually happens after vesting. income on w-2's is ordinary income
the loss you say you incurred in the sale of RSU's is a capital loss. at most only $3,000 of net capital losses for the year can be deducted against ordinary income
this is from an article in Forbes
According to the IRS rules for supplemental wage income, such as income from the vesting of restricted stock or RSUs, your company must withhold tax at a flat rate of 22%. (The rate jumps to 37% for income amounts in excess of $1 million during the calendar year.)
so some shares should have been sold to cover the required withholding. if not, this can result in a substantial penalty that the IRS can levy against the company.
so in figuring the tax you owe it would likely be your marginal tax bracket rate times the value of the stock to be added to your w-2 less whatever was withheld. we don't know your marginal tax bracket. It is not the effective tax rate that Turbotax shows on the filing instructions. The marginal tax bracket is shown in the tax history report. I don't know if all versions of Turbotax produce this report.
don't forget about state taxes if you are subject to them.
you should discuss with your company the ability to sell additional shares upon vesting so your full tax liability is covered.
