Here's what you need to know.
1. HHS Inspector General Daniel R. Levinson told Senator Charles Grassley (R-Iowa) of the findings Oct. 8, 2016. Mylan agreed to a $465 million settlement with CMS last month.
2. The disclosure from HHR raise questions on why Mylan took so long to correct the error, what steps CMS took to inform Mylan of the error and why Mylan didn't disclose the information with its investors.
3. U.S. Securities regulators issued a subpoena for Mylan's communications with CMS.
