Any percentage of match is potentially a cause for concern for learners working on their comprehensive exam or dissertation.  However, the score itself is less important than the details of the Originality Report.  It is very important to carefully review the report for any evidence of missing citations or plagiarized text and to rewrite plagiarized text by paraphrasing or summarizing.  Your goal should be for Turnitin to highlight as “matching” only directly quoted text, inline citations, and common phrases that do not need to be paraphrased, such as “arrange a meeting.”

Find resources for using Turn-It-In and Interpreting the Originality Report