The IRS in Notice 2016-9 gave social welfare organizations additional time to notify the IRS of their intent to operate under IRC §501(c)(4) under IRC §506 that was added by the Protecting Americans from Tax Hikes Act of 2015 (PATH).  This new requirement applies to §501(c)(4) social welfare organizations established after December 18, 2015 and certain other organizations already in existence. 

The due date for notifications of intent to operate under IRC §501(c)(4) will be no earlier than 60 days after the publication of regulations that will prescribe the manner in which such organizations must notify the IRS.  At that point they will submit the information required by IRC §506.