grants or our annual grant program, the Compensation Committee retains discretion to grant equity awards to employees at other times, including in connection with the promotion of an employee, to reward an employee, for retention purposes or for other circumstances recommended by management or the Compensation Committee.
The exercise price of each stock option grant is the fair market value of our Common Stock on the grant date. Time-based stock option awards granted to our Named Executive Officers generally vest over a four-year period as follows: 25% of the shares underlying the option vest on the first anniversary of the date of the vesting commencement date and the remainder of the shares underlying the option vest in equal monthly installments over the remaining 36 months thereafter. From time to time, our Compensation Committee may, however, determine that a different vesting schedule is appropriate. We do not have any stock ownership requirements for our Named Executive Officers.
2018 Awards Granted – Time-Based Stock Options
In January 2018, the Board, based upon a recommendation by the Compensation Committee, awarded annual stock options to our Named Executive Officers based on its review of the foregoing factors and comparable company information. These awards are described in detail in the Outstanding Equity Awards as of December 31, 2018 table below. The stock options are subject to our standard time-based four-year vesting schedule described above.
The Boards determination regarding each Named Executive Officers annual award amount was not based on any quantifiable factors, but instead was based on the Compensation Committees subjective analysis of the award levels the Compensation Committee deemed appropriate for each executive in light of various factors, including the fact that each executives base salary remained below the 50th percentile for the Companys peer group for 2015. The final award levels, however, were entirely based on the Compensation Committees subjective analysis of these general factors and internal pay equity considerations.
Employee Benefit Program
Executive officers, including the Named Executive Officers, are eligible to participate in all of our employee benefit plans, including medical, dental, vision, group life, disability and accidental death and dismemberment insurance, in each case on the same basis as other employees, subject to applicable law. We also provide vacation and other paid holidays to all employees, including executive officers. These benefit programs are designed to enable us to attract and retain our workforce in a competitive marketplace. Health, welfare and vacation benefits ensure that we have a productive and focused workforce through reliable and competitive health and other benefits.
Our retirement savings plan (401(k) Plan) is a tax-qualified retirement savings plan, pursuant to which eligible employees can begin to participate immediately upon employment. The 401(k) Plan elective deferrals and employer contributions are subject to compensation limitations and annual maximum contribution limits as governed by Internal Revenue Service. Employees are eligible to defer up to 100% of compensation and the Company makes safe harbor matching contributions of 100% match of first 3% of compensation contributed, then 50% match of next 2% of compensation contributed.