Lockheed Martin Corp., Manassas, Virginia (N0001922D0017 P00001); Undersea Sensor Systems Inc., Columbia City, Indiana (N0001922D0018 P00001); and Sparton De Leon Springs, LLC. De Leon Springs, Florida (N0001922D0019 P00001) are awarded an estimated aggregate ceiling of $5,100,000,000 for firm-fixed-price modifications to a previously awarded indefinite-delivery/indefinite-quantity contract. These modifications exercise options for the production and delivery of the following sonobuoy capability categories: bathythermograph, passive, active/passive combo, multistatic source, multistatic receiver, and special mission in support of annual training, peacetime operations and testing expenditures, as well as, to maintain sufficient inventory to support the execution of Major Combat Operations based on Naval Munitions Requirements Process. The companies have an opportunity to compete for individual orders. Lockheed Martin Corp. will perform work in Manassas, Virginia; Undersea Sensor Systems Inc. will perform work in Columbia City, Indiana, while Sparton De Leon Springs, LLC will perform work in De Leon Springs, Florida, and is expected to be completed in September 2027. No funds will be obligated at the time of award. Funds will be obligated on individual orders as they are issued. The Naval Air Systems Command, Patuxent River, Maryland, is the contracting activity.