Option period
(h) Option period(1) An employee stock purchase plan or offering must, by its terms, provide that options granted under the plan cannot be exercised after the expiration of 27 months from the date of grant unless, under the terms of the plan or offering, the option price is not less than 85 percent of the fair market value of the stock at the time of the exercise of the option. If the option price is not less than 85 percent of the fair market value of the stock at the time the option is exercised, then the option period provided under the plan must not exceed five years from the date of grant. If the requirements of this paragraph (h) are not met by the terms of the plan or offering, then options issued under such plan or offering will not be treated as options granted under an employee stock purchase plan irrespective of whether the options, by their terms, are exercisable beyond the period allowable under this paragraph (h). An option that provides that the option price is not less than 85 percent of the fair market value of the stock at exercise may have an option period of 5 years irrespective of whether the fair market value of the stock at exercise is more or less than the fair market value of the stock at grant. However, if the option provides that the option price is 85 percent of the fair market value of the stock at exercise, but not more than some other fixed amount determined in accordance with the provisions of paragraph (g) of this section, then irrespective of the price paid on exercise, the option period must not be more than 27 months.