The Alliance of Claims Assistance Professionals originated as the National Association of Claims Assistance Professionals (NACAP). Headquartered in Downers Grove, Illinois, NACAP was a non-profit 501c(3) corporation that debuted in 1991 under the direction of Norma Border and Kathryn Dokas. The mission of NACAP was to educate and certify new members and promote the CAP industry. NACAP ceased operating in 1998.

In 1998, recognizing the need for a central CAP directory and ongoing member education, several former NACAP members created the Alliance of Claims Assistance Professionals (ACAP), a non-profit 501c(3) corporation headquartered in Wheaton, Illinois. For a time, ACAP also offered certification examinations for both CAPs and ECPs (Electronic Claims Assistance Professionals). The corporation is managed by a volunteer Board of Directors.