Toyota will now spend almost US$13bn by 2021 at its US operations and will add about 600 new jobs.
It will also build hybrid versions of the popular RAV4 and Lexus ES in Kentucky for the first time.
Production capacity will be increased and buildings expanded at plants in Huntsville, Alabama, Buffalo, West Virginia, Troy, Missouri, and Jackson, Tennessee.
The company had in 2017 pledged to invest $10bn over five years.
As well as adding the hybrid output at Kentucky, Toyota will expand engine capacity at Huntsville, Alabama; double hybrid transaxle capacity in Buffalo, West Virginia; and expand a building for additional castings at Bodine Aluminum's Jackson, Tennessee, facility as well as additional castings at its Troy, Missouri, facility.
"These latest investments represent even more examples of our long-term commitment to build where we sell," said Jim Lentz, chief executive officer for Toyota Motor North America.
"By boosting our US manufacturing footprint, we can better serve our customers and dealers and position our manufacturing plants for future success with more domestic capacity."
New investments totaling $749m and 586 new jobs state by state:
Alabama Toyota Motor Manufacturing, Alabama (TMMAL) – $288,000,000
Increase annual engine capacity from 670,000 to 900,000 by the end of 2021 to increase product flexibility and better accommodate market demand. New four cylinder and V6 engine lines will add 450 new jobs at the Huntsville, Alabama, facility, the largest hiring need in the plant's history. The investment also includes a building expansion.
Kentucky Toyota Motor Manufacturing, Kentucky (TMMK) – $238,000,000
This vehicle plant, the company's largest globally, will begin production of the Lexus ES 300h hybrid in May 2019 with annual capacity of 12,000 units while RAV4 Hybrid production will start January 2020 with an annual capacity of 100,000 units.
Missouri Bodine Aluminum Troy, Missouri – $62,000,000
Investments will provide equipment to produce an additional 864,000 cylinder heads for Toyota's New Global Architecture (TNGA).
Tennessee Bodine Aluminum Jackson, Tennessee – $50,000,000
This investment includes a building expansion and equipment to double the capacity of hybrid transaxle cases and housings to 240,000 annually. The investment will also provide equipment to produce an additional 288,000 engine blocks a year for TNGA.
West Virginia Toyota Motor Manufacturing, West Virginia (TMMWV) – $111,000,000
The investment includes a building expansion and equipment to double capacity of hybrid transaxles from 120,000 units (from start of production in 2020) to 240,000 units annually in 2021. To meet the production demands, TMMWV will add 123 new jobs to its facility in Buffalo.