MERCURY SYSTEMS INC

1. The transaction reported herein was effected for the purpose of rebalancing the holdings of funds and accounts managed by JANA (as defined below).

2. JANA Partners Management, LP ("JANA" or the "Reporting Person") is a private money management firm which beneficially owns the securities reported herein through various accounts under its management and control. JANA Partners Management GP, LLC (the "GP") is the general partner of JANA. Barry Rosenstein is the Founder of the GP and JANA. JANA, the GP and Barry Rosenstein disclaim any beneficial ownership of any of the Issuer's securities reported herein except to the extent of their pecuniary interest therein, if any.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.98 to $90.21, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range set forth herein.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.65 to $89.72, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth herein.