401(k) Plan	12 Months Ended
Dec. 31, 2018
401(k) Plan
401(k) Plan	10. 401(k) Plan We have a 401(k) plan covering all full‑time employees. Employees may make pre‑tax contributions up to the maximum allowable by the Internal Revenue Code. Effective January 1, 2018, the Company contributes 100% of the first 1% of participating employees’ contribution and 50% of the next 5% of participating employees’ contribution, for a maximum of 3.5% employer contribution. Participants are immediately vested in their employee contributions; employer contributions are vested over a three-year period with one-third for each year of a participating employee’s service. Employer contributions made for the year ended December 31, 2018 was $0.5 million. No employer contributions were made for the years ended December 31, 2017 and 2016.

401(k) Plan

12 Months Ended

Dec. 31, 2018

10. 401(k) Plan

We have a 401(k) plan covering all full‑time employees. Employees may make pre‑tax contributions up to the maximum allowable by the Internal Revenue Code. Effective January 1, 2018, the Company contributes 100% of the first 1% of participating employees’ contribution and 50% of the next 5% of participating employees’ contribution, for a maximum of 3.5% employer contribution. Participants are immediately vested in their employee contributions; employer contributions are vested over a three-year period with one-third for each year of a participating employee’s service. Employer contributions made for the year ended December 31, 2018 was $0.5 million. No employer contributions were made for the years ended December 31, 2017 and 2016.