Lockheed Martin Rotary and Mission Systems, Moorestown, New Jersey, is being awarded an undefinitized contract action (UCA), with a not-to-exceed value of $527,740,864, inclusive of all options. This UCA will be awarded for a sole-source, hybrid (cost-plus-incentive-fee and cost-plus-fixed-fee) modification (P00054) under contract HQ085121C0002. This UCA expands performance of the Aegis Weapon System to implement Integrated Air and Missile Defense capabilities into an Aegis Guam System. An initial obligation of $11,394,512 using fiscal 2023 research, development, test and evaluation funds will occur at the time of award. The work will be performed in Moorestown, New Jersey, with period of performance from time of award through Dec. 31, 2027. The value of the contract increases from $811,633,012 by $425,365,356 to $1,236,998,368. The Missile Defense Agency, Dahlgren, Virginia, is the contracting activity.