General Dynamics Mission Systems Inc., Scottsdale, Arizona, is awarded an $88,490,500 modification to an indefinite-delivery/indefinite-quantity contract (N00039-24-D-2000) for the procurement, manufacturing, testing, and delivery of AN/USC-61(C) Digital Modular Radio (DMR) systems, High Frequency Distribution Amplifier Group components, and spares for both systems. This modification increases the value of the basic contract by $88,490,500, to a new total contract value of $171,299,517. DMR is a modular, software reprogrammable radio system with embedded cryptography that provides all radio frequency (RF) to-baseband and baseband-to-RF conversion functions required for line-of-sight (LOS), beyond LOS and satellite communications systems operating between 2.0 megahertz to 2.0 gigahertz. This contract action was not competitively procured because it is a sole source acquisition pursuant to the authority of 10 U.S. Code 2304(c)(1) – Only One Responsible Source (Federal Acquisition Regulation Subpart 6.302-1). Work will be performed in Scottsdale, Arizona and is expected to be completed by February 2029. No funds will be obligated at the time of modification award. The Naval Information Warfare Systems Command, San Diego, California, is the contracting activity (N00039).