This excerpt taken from the TPTX DEF 14A filed Apr 24, 2008.
Federal Income Tax Information
Rights granted under the Purchase Plan are intended to qualify for favorable federal income tax treatment associated with rights granted under an employee stock purchase plan which qualifies under provisions of Section 423 of the Code.
A participant will be taxed on amounts withheld for the purchase of shares of Common Stock as if such amounts were actually received. Other than this, no income will be taxable to a participant until disposition of the acquired shares, and the method of taxation will depend upon the holding period of the acquired shares.
If the stock is disposed of more than two years after the beginning of the offering period and more than one year after the stock is transferred to the participant, then the lesser of (i) the excess of the fair market value of the stock at the time of such disposition over the exercise price or (ii) the excess of the fair market value of the stock as of the beginning of the offering period over the exercise price (determined as of the beginning of the offering period) will be treated as ordinary income. Any further gain or any loss will be taxed as a long-term capital gain or loss. At present, such capital gains generally are subject to lower tax rates than ordinary income.
If the stock is sold or disposed of before the expiration of either of the holding periods described above, then the excess of the fair market value of the stock on the exercise date over the exercise price will be treated as ordinary income at the time of such disposition. The balance of any gain will be treated as capital gain. Even if the stock is later disposed of for less than its fair market value on the exercise date, the same amount of ordinary income is attributed to the participant, and a capital loss is recognized equal to the difference between the sales price and the fair market value of the stock on such exercise date. Any capital gain or loss will be short-term or long-term, depending on how long the stock has been held.
There are no federal income tax consequences to us by reason of the grant or exercise of rights under the Purchase Plan. We are entitled to a deduction to the extent amounts are taxed as ordinary income to a participant (subject to the requirement of reasonableness and the satisfaction of tax reporting obligations).