Rev. Proc. 64-25

A ruling or determination letter holding an organization of the type contributions to which are deductible under section 170 of the Internal Revenue Code of 1954 is effective only so long as there has been no material change in the character, the purpose, or the method of operation of the organization. If such a ruling is revoked or modified, the revocation or modification applies to all open years under the statutes, unless the Commissioner exercises the discretionary powers given to him under section 7805(b) of the Code to limit the retroactive effect of the ruling.

Therefore, where an organization has been held to be of the type contributions to which are deductible under section 170 of the Code, and the Internal Revenue Service, by a ruling or a determination letter, subsequently holds that it is not such an organization, contributions made to the organization by persons unaware of such new ruling or determination letter generally will be considered allowable (1) until the date that an announcement is published in the Internal Revenue Bulletin or otherwise made public to the effect that contributions are no longer deductible, or (2) until the termination date stated in such an announcement. However, this will not preclude the Service, in appropriate cases, from disallowing any contributions made before either of such dates where the contributor, prior to the publication of such announcement, (1) had knowledge of the new ruling or determination letter, (2) was aware that its issuance was imminent, or (3) was in part responsible for the activities or deficiencies which gave rise to its issuance. Also, see section 503(e) of the Code and section 1.503(e)-1 of the Income Tax Regulations.