Reading A-Z and Readworks.org have materials for leveled reading. Reading A-Z offers users almost 1,000 books in 27 levels. There are several free samples of books and supplemental materials available for download. Users can also sign up for a free trial. As of 2015, a year-long subscription cost $99.95.
Readworks.org has many reading passages that are categorized by grade, Lexile level, topic, text type and strategy. Users can also search passages by those categories and keywords. Some of the passages come with questions, stepreads, paired texts and vocabulary. The website also offers many teaching resources, such as free lesson plans and comprehension worksheets.