There is no automatic termination date for a 501(c)(3) exemption or for any of the 28 other exempt status designations under Section 501(c) of the Tax Code.  Exempt status continues so long as the organization meets the requirements for qualification and the IRS has not revoked its status.

There is an automatic termination, however, for failure to file a tax information return for three years in a row. Even small  organizations, now those with annual revenues of less than $50,000, must file the Form 990-N electronic postcard.  (See Ready Reference Page: "Small Nonprofits Must File E-Postcard to Retain Exemption")