UpToDate topics may be cited similarly to book chapters, although there are no page numbers to cite since UpToDate is an online resource. The last updated date should be used for the current year. For example, in APA style:
Notes from APA Style Blog:
"We encourage the use of UpToDate materials for teaching purposes. It's important to keep in mind that UpToDate material is protected by copyright. However, topics, graphics, and charts may be reproduced for use as screen shots in slide presentations, or printed for distribution at lectures, courses, and other educational venues within the provisions of our license agreement. Materials must be reproduced directly from UpToDate so that the copyright statement is visible or cited as a source reference (see above) and must be distributed free of charge." (Wolters Kluwer, 2023)
"All UpToDate material is protected by copyright. Permission to reproduce material from UpToDate (including figures, tables, and portions of topics) in another publication must be secured in writing. You must obtain express written consent from UpToDate in order to use on your website any content provided on the UpToDate Website. Download the Permission to Use or Reproduce UpToDate Material request form here." (Wolters Kluwer, 2023)