Section 504(a) and this section apply to an organization that is exempt from taxation at any time after October 4, 1976, as an organization described in section 501(c)(3), and that ceases to be described in that section because it--
(a) Is an action organization within the meaning of Sec. 1.501(c)(3)-1(c)(3)(ii) or (iv), on account of activities occurring after October 4, 1976, or
(b) Is denied exemption under the provisions of section 501(h) (see Sec. 1.501(h)-3 or Sec. 56.4911-9). This section does not apply, however, to an organization that was described in section 501(h)(5) and Sec. 1.501(h)-2(b)(3) (relating generally to churches) for its taxable year immediately preceding the first taxable year for which it is no longer an organization described in section 501(c)(3). An organization to which section 504(a) and this section apply shall not be treated as described in section 501(c)(4) at any time after the organization ceases to be described in section 501(c)(3). Further, an organization denied treatment as an organization described in section 501(c)(4) under this section may not be treated as an organization described in section 501(c) other than as an organization described in section 501(c)(3). For rules relating to recognition of exemption after exemption is denied under section 501(h), Sec. 1.501(h)-3(d). [T.D. 8308, 55 FR 35592, Aug. 31, 1990]