Your CITI Program Completion Report has two parts. Part 1 shows quiz scores at the time you "completed and passed" the course requirements, and is "frozen" thereafter. Part 2 is continually updated.
Once a Completion Report has been issued you will not be able to change the scores on Part 1, which is called the "requirements report." However, Part 2, the "transcript report," will reflect new scores if you subsequently retake any quizzes, including quizzes on supplemental (optional) modules that were not part of the original course requirements.
To "complete and pass" a course you must complete all quizzes for required modules and, if any, also quizzes for the minimum number of elective modules. In doing so, you must meet or exceed the required minimum average score set by your institution for that course. Note that some institutions also set a per-module minimum score for each quiz, in addition to requiring an average minimum score for the course quizzes overall.
Note that new quiz completions also will not change any information on the associated Completion Certificate for the course, since the Certificate does not contain any quiz scores and is not updated based on new quiz attempts after you have completed and passed the course.
You will be prompted to renew when your course nears expiration, if your institution has set an expiration date for it. (This date is shown on both the Completion Report and Completion Certificate.)
You may also review your expiration dates through the "My Records" link on your learner menu. If you wish to renew early, please consult with your institution's CITI administrator.