Over 40 states have adopted the Common Core State Standards in Mathematics. This is a strong, coherent set of standards that asks students to understand and explain mathematical ideas and lines of reasoning, actively make sense of mathematics, discuss their reasoning, explore and develop ideas, solve problems, and develop fluency with important skills. But as strong as the Common Core standards are, they cannot improve students’ understanding of mathematics on their own. Teachers are certainly key to enacting the standards as they are intended. They need to know the mathematics well, and they need to how to teach it in engaging and effective ways. In this editorial, I want to make the case for the group of all mathematics teachers—from early childhood, to the elementary, middle, and high school grades, through the college and graduate levels, and including mathematics educators who teach teachers— to form a cohesive community that works together with the common goal of improving mathematics teaching at all levels. I will draw on my knowledge of the mathematics research community and how it is set up to work towards excellence in mathematics research. I will also contrast research in mathematics and teaching of college-level mathematics, much of which is done by the same group of people.