I imported my 1099-B. My 'tax due' skyrocketed, as a result. I paid taxes at the time I exercised my options so I know something is off. I have a 'supplemental information' page included with my 1099-B that has an 'adjusted cost or other basis' column that is significantly higher than the 'cost basis' on my 1099-B. Is this the reason why my tax burden jumped? Do I enter the adjusted cost basis from my 1099 supplemental sheet? Thank you.
