An unnamed foreign customer is paying Lockheed Martin $18.8 million for further development and integration work on an F-35 fighter jet variant tailored to its specific requirements, extending a program that has received multiple contract modifications over the past several years.
The US Department of War announced the latest award on October 15, describing it as an $18.79 million modification to an existing contract with Lockheed Martin Aeronautics. The work covers system development, demonstration, and integration efforts for an F-35 variant configured for an undisclosed Foreign Military Sales (FMS) customer.
The foreign customer is funding the entire amount, with the money obligated at the time of the award. Work will be performed primarily in Fort Worth, Texas, where Lockheed Martin manufactures the aircraft, and at other undisclosed locations in the continental United States. Completion is expected in December 2030, according to the official contract announcement.
The award does not represent a purchase of a new fighter jet. Instead, it adds engineering and integration work to an existing contract, allowing the customer to pursue a version of the aircraft adapted to its requirements.
A country-specific F-35 variant remains unidentified
The Pentagon has not publicly named the customer behind the latest modification. The contract falls under the US Foreign Military Sales program, through which the US government facilitates arms sales to foreign governments.
Such arrangements can involve modifications to standard military equipment to meet a buyer’s operational needs. For the F-35, these requirements can include country-specific communications systems, weapons integration, or electronic warfare capabilities. However, the latest contract announcement does not specify which features are being developed for this customer.
The F-35 family consists of three variants. The F-35A is designed for conventional takeoff and landing, the F-35B is capable of short takeoff and vertical landing, and the F-35C is carrier-based.
Israel’s F-35I Adir is a prominent example of a country-specific configuration. It is based on the F-35A but incorporates Israeli-developed systems. However, there is no public evidence in the latest award identifying Israel, or any other country, as the customer behind the current contract.
Contract builds on earlier development work
The latest modification continues a longer-running effort to develop and integrate a tailored F-35 configuration. The US Navy awarded Lockheed Martin a $53.4 million contract modification in August 2022 for continued engineering work on a Joint Strike Fighter variant adapted for an unnamed foreign customer. A further modification worth $12.9 million followed in August 2025.
The new award, designated modification P00011 under contract N0001922C0015, adds another $18.79 million to the effort. The contract combines cost-plus-incentive-fee and firm-fixed-price arrangements, according to the Pentagon’s announcement.
The repeated awards indicate that development and integration work has continued over several years. However, the available contract notices do not identify the exact systems being modified, the customer, or when the tailored configuration might enter service.
F-35 production continues at scale
The latest award comes as Lockheed Martin continues producing the F-35 for the US military and international customers. The aircraft is operated by the United States and multiple allied nations, making compatibility with different national requirements an important part of its international program.
Country-specific adaptations can help customers integrate the aircraft into their existing defense networks, but they can also require additional engineering, testing, and certification.
The $18.8 million modification confirms that work on the unidentified customer’s tailored F-35 variant is continuing through the end of the decade. Until the Pentagon or the customer releases further details, the identity of the buyer and the precise capabilities being developed remain undisclosed.