The SPEX consists of three separately timed components. The first component is a tutorial containing sample SPEX items and is provided before the start of the examination. The tutorial allows examinees to become familiar with the computer, the layout of the screens, the function of the mouse and keyboard, and methods to access different screens (e.g., Drugs Names, Laboratory Values, Item Review Screen).

The examination itself is divided into 8 blocks of 52 minutes each (50 questions in each block). Timing for each section of SPEX is computer-controlled, and a "Time Remaining" box is displayed on the computer screen. Examinees should try to answer every test item as there is no penalty for guessing. Examinees should try to complete every block of the examination. If an examinee chooses to leave the testing center before completing the exam, the administration will be considered incomplete. An incomplete or partial administration may affect reexamination procedures.

During the computer administration, examinees may return at any time to marked or incomplete items within a block using the Item Review Screen, as long as time remains in that block and the examinee has not exited the block. The Item Review Screen allows examinees to monitor their progress and review marked or incomplete items before the block time expires. Once a block is exited, examinees will not be allowed to return to that block. The test session ends when all blocks have been completed (or the total time for the test expires).