The Missile Defense Agency (MDA) awarded Lockheed Martin [LMT] a $459 million modification on Jan. 26 to produce additional Lot 10 Terminal High Altitude Area Defense (THAAD) interceptors.

The modification exercises an option on a previously-awarded contract for these additional interceptors and provide associated production support efforts under fixed-price incentive-firm target contract line item numbers.

Last March MDA awarded Lockheed Martin a $273 million contract for Lot 9 of these THAAD missile defense interceptors. Then this past December MDA awarded Lockheed a $553 million modification for additional Lot 9 and the first Lot 10 interceptors.

That December award included this $459 million option for additional Lot 10 interceptors.

This award increases the contract’s total value from $827 million to about $1.3 billion. The work is expected to be finished by June 2021.

In November, the Trump administration requested $2.1 billion in fiscal year 2018 budget amendments to procure 50 new THAAD interceptors, 20 new ground-based Midcourse Defense (GMD) Ground-Based Interceptors (GBIs), and 15 Standard Missile-3 Block IIA interceptors.

In December President Trump signed into law a continuing resolution that provided $4.7 billion in emergency funding for Navy ship repairs and ballistic missile defense the administration requested.

A Lockheed Martin spokesperson told sister publication Defense Daily in a statement that this new modification is a result of the supplemental funding.

The company also said no Lot 10 missiles have not been produced yet because they have about a three-year lead time.