The IRS Revenue Ruling 79-359, 1979-2 C.B. 226 specifies that a qualifying organization whose purpose is to provide burial services that directly support and maintain basic tenets of a religion is operated exclusively for charitable purposes and is exempt from tax under section 501(c)(3) of the Code. In addition, the ruling recognizes that such organizations may receive fees in order to provide the burial services. Summum's rites of Mummification and Transference fall under this rule.
In a letter to Summum dated May 28, 1986, the Internal Revenue Service specifically ruled that conducting and facilitating Mummification and Transference in accordance with Summum's religious precepts does not change Summum's federal tax exempt status. You may read excerpts from the ruling by accessing the link below: