The national requirements for individual membership in a local chapter are as follows. These are the minimum requirements; chapters may elect to have stricter standards but not lower ones. Students are encouraged to participate in Mu Alpha Theta club meetings and activities, even if they do not qualify as members.

Membership, High School Chapter:

- Members must be high school students in grades 9 through 12.
- Members must be registered with Mu Alpha Theta at the school at which  their permanent records reside.
- Members must have completed the equivalent of two years of college preparatory mathematics, including algebra and/or geometry, and have completed or are enrolled in a third year of college preparatory mathematics.
- On the 4-point grading scale, members must have at least a 3.0 math grade point average.