ACHN 2018 Proxy Statement

In accordance with Item 402(u) of Regulation S-K, we identified the median employee as of October 2, 2017 by (i) aggregating for each applicable employee (A) annual base salary for salaried employees (or hourly rate multiplied by expected annualized work schedule, for permanent hourly employees), (B) the target incentive compensation for 2017, assuming a payout at a target level of performance, and (C) the accounting value of any equity awards granted during 2017 and, (ii) ranking this compensation measure for our employees from lowest to highest. This calculation was performed for all 83 of our employees as of October 2, 2017, excluding Dr. Deshpande. The pay ratio reported above is a reasonable estimate calculated in a manner consistent with SEC rules based on our internal records and the methodology described above. The SEC rules for identifying the median compensated employee and calculating the pay ratio based on that employee’s annual total compensation allow companies to adopt a variety of methodologies, to apply certain exclusions, and to make reasonable estimates and assumptions that reflect their employee populations and compensation practices. Therefore, the pay ratio reported by other companies may not be comparable to the pay ratio reported above, as other companies have different employee populations and compensation practices and may utilize different methodologies, exclusions, estimates and assumptions in calculating their own pay ratios. 47