One can apply for the SMS exam with this application. If you didn't pass the initial exam, you can use this application to retake the exam.
Please note that the SMS exam will be on hiatus and unavailable starting November 1, 2023 through January 31, 2024. Exam scheduling will then resume in February 2024. This is because the SMS exam is in the process of being updated.
DO NOT SNAIL MAIL your application to the office. Sending your application in the mail will delay processing.
See the SMS Exam reference materials page, which contains books, articles, and web resources that can help prepare you for the SMS exam.