- Read Works: ReadWorks provides research-based units, lessons, and authentic, leveled non-fiction and literary passages directly to educators online, for free! K-8
- Vale Middle School: This site has articles and questions for Lexile level 900 and up. Free
- Kelly Gallagher: This site has articles and questions. The articles are assigned to high school students, but many could be used for middle school too. Free
- Teaching the Core: This site has great articles for middle schoolers. Free
As I find more sites with articles I will update the post. If you have any sites please comment with the site below.