Capital Stock	3 Months Ended
Mar. 31, 2017
Capital Stock
Capital Stock	F. Capital Stock 2001 Non-Employee Director Stock Plan During the three months ended March 31, 2017, the Company recorded approximately $12,000 in expense related to stock units outstanding under the Company’s 2001 Non-Employee Director Stock Plan, or the 2001 Plan, compared to ($32,000) in expense reduction recorded during the three months ended March 31, 2016. The value of the stock units are classified as a liability and adjusted to market value at each reporting period as the redemption amount of stock units for this plan will be paid in cash. No stock units have been issued under the 2001 Plan subsequent to June 30, 2004. Compensation Policy for Non-Employee Directors On December 9, 2016 the Board amended the Compensation Policy for Non-Employee Directors to create a transition period due to the change in the year-end. Effectively, one-half of the annual compensation awards described below were awarded to the directors on December 9, 2016 and a full-year’s compensation will be awarded at the date of the next annual meeting. Pursuant to the Compensation Policy for Non-Employee Directors, the redemption amount of deferred share units issued will be paid in shares of common stock of the Company on the date a director ceases to be a member of the Board. Annual retainers vest quarterly over approximately one year from the date of grant, contingent upon the individual remaining a director of ImmunoGen as of each vesting date. The number of deferred share units awarded is fixed per the plan on the date of the award. All unvested deferred stock awards will automatically vest immediately prior to the occurrence of a change of control. During the three months ended March 31, 2017, the Company recorded approximately $38,000 in compensation expense, respectively, related to deferred share units issued and outstanding under the Company’s Compensation Policy for Non-Employee Directors, compared to $108,000 in compensation expense recorded during the three months ended March 31, 2016. Pursuant to the Compensation Policy for Non-Employee Directors, in January 2017, the Company issued a retiring director 53,248 shares of common stock of the Company to settle outstanding deferred share units. In addition to the deferred share units, the Non-Employee Directors are also entitled to receive a fixed number of stock options determined using the Black-Scholes option pricing model measured on the date of grant, which would be the date of the annual meeting of shareholders. These options vest quarterly over approximately one year from the date of grant. Any new directors will receive a pro-rated award, depending on their date of election to the Board. The directors received a total of 80,000 stock options in November of 2015 and a total of 40,000 options in December 2016, and the related compensation expense for the three months ended March 31, 2017 and 2016 is included in the amounts discussed in the “Stock-Based Compensation” section of footnote B above.

F. Capital Stock

2001 Non-Employee Director Stock Plan

During the three months ended March 31, 2017, the Company recorded approximately $12,000 in expense related to stock units outstanding under the Company’s 2001 Non-Employee Director Stock Plan, or the 2001 Plan, compared to ($32,000) in expense reduction recorded during the three months ended March 31, 2016. The value of the stock units are classified as a liability and adjusted to market value at each reporting period as the redemption amount of stock units for this plan will be paid in cash. No stock units have been issued under the 2001 Plan subsequent to June 30, 2004.

Compensation Policy for Non-Employee Directors

On December 9, 2016 the Board amended the Compensation Policy for Non-Employee Directors to create a transition period due to the change in the year-end. Effectively, one-half of the annual compensation awards described below were awarded to the directors on December 9, 2016 and a full-year’s compensation will be awarded at the date of the next annual meeting.

Pursuant to the Compensation Policy for Non-Employee Directors, the redemption amount of deferred share units issued will be paid in shares of common stock of the Company on the date a director ceases to be a member of the Board. Annual retainers vest quarterly over approximately one year from the date of grant, contingent upon the individual remaining a director of ImmunoGen as of each vesting date. The number of deferred share units awarded is fixed per the plan on the date of the award. All unvested deferred stock awards will automatically vest immediately prior to the occurrence of a change of control.

During the three months ended March 31, 2017, the Company recorded approximately $38,000 in compensation expense, respectively, related to deferred share units issued and outstanding under the Company’s Compensation Policy for Non-Employee Directors, compared to $108,000 in compensation expense recorded during the three months ended March 31, 2016. Pursuant to the Compensation Policy for Non-Employee Directors, in January 2017, the Company issued a retiring director 53,248 shares of common stock of the Company to settle outstanding deferred share units.

In addition to the deferred share units, the Non-Employee Directors are also entitled to receive a fixed number of stock options determined using the Black-Scholes option pricing model measured on the date of grant, which would be the date of the annual meeting of shareholders. These options vest quarterly over approximately one year from the date of grant. Any new directors will receive a pro-rated award, depending on their date of election to the Board. The directors received a total of 80,000 stock options in November of 2015 and a total of 40,000 options in December 2016, and the related compensation expense for the three months ended March 31, 2017 and 2016 is included in the amounts discussed in the “Stock-Based Compensation” section of footnote B above.