The NGSS were approved by the Kentucky Board of Education at their June 5, 2013 meeting. The science standards have completed the legislative review process and are now incorporated into the Kentucky Academic Standards for implementation in the classroom.
The NGSS were based on the Framework for K-12 Science Education published by the National Academies Press and available to download or read online for free. A brief outlining the Framework is also available to download.
The standards along with several supporting documents are available from the Next Generation Science Standards website.