For secondary teachers of mathematics, science, and technology, Real World Externships help them answer the legitimate student query: “Why am I ever gonna need to know this?” with real challenges and problems encountered and solved in actual companies. The Iowa Mathematics and Science Education Partnership (IMSEP), in collaboration with teachers and Iowa business/industry partners, have placed teachers of mathematics, science, and technology into local businesses and agencies throughout Iowa for six-week-long summer immersions in real projects as externs. Real World Externships for Teachers of Mathematics, Science, and Technology was piloted in 2009 to build bridges between the business and education worlds. The program has grown to be available across the state with over 30 Iowa business partners in 2011. This program provides Iowa’s math and science teachers an opportunity to experience the latest real world application of their disciplines. Teachers bring back their experiences by designing hands-on, minds-on problem-solving activities for students in the classroom to spark interest in pursuing careers in STEM fields in Iowa. Businesses meanwhile, enjoy the contributions of autonomous, industrious, creative, and bright partners in solving challenges. This chapter provides detailed information about this program from it’s goals to the program’s successes and how it has evolved.