Note 8 — Equity Incentive Plan

In May 2013, the Company adopted the 2013 Equity Incentive Plan (the “Plan”) and reserved shares of common stock for issuance under the Plan, which was amended effective June 16, 2020. As a result of the amendment, the number of shares authorized for issuance under the Plan increased by 350,000 shares and the Plan will now terminate on June 16, 2030, unless sooner terminated or extended by the Board. The Plan is administered by the Compensation Committee of the Company’s Board of Directors.

At June  30, 2020, 262,861 shares of common stock were available for issuance under the Plan.

A summary of the Company’s stock option activity and related information is as follows:

During the six months ended June 30, 2020, the Company granted 52,791 stock options to Board members, 57,000 stock options to executives and  3,000 stock options to employees under the Plan. The estimated fair value of these stock options, calculated using the Black-Scholes option valuation model, was $173,184, of which $123,725 was recognized during the six months ended June 30, 2020.

In April 2020, the Board approved a modification of a stock option grant to Dr. Lon E. Bell in connection with his retirement as Chief Executive Officer and President. The modification accelerated the vesting of Dr. Bell's October 2019 stock option grant with full vesting effective immediately prior to the end of Dr. Bell's term on the Board in June 2020. During the three months ended June 30, 2020, the Company recognized $79,444 of expense related to this grant subsequent to the modification.

At June 30, 2020, there was $104,822 of unrecognized compensation cost related to non-vested equity awards granted under the Plan. That cost is expected to be recognized over a weighted average period of 0.8 years.