There are several agencies you may contact to verify actuarial credentials.
Joint Board for the Enrollment of Actuaries Internal Revenue Service (JBEA)
1111 Constitution Avenue NW
Washington, DC 20224
The JBEA regulates the credentialing of actuaries practicing in the pension field and issues pension actuaries' enrollment numbers. Enrolled Actuaries may use the initials EA.
American Academy of Actuaries
1100 17th Street NW 7th Floor
Washington, DC 20036
The American Academy of Actuaries is a professional organization of actuaries practicing mainly in the United States and Canada. Members may use the initials MAAA (Member, American Academy of Actuaries).
Society of Actuaries
475 North Martingale #600
Schaumburg, Illinois 60173
The Society of Actuaries (SOA) administers examinations that lead to professional designation of Associate or Fellow of the SOA (ASA or FSA).
Conference of Consulting Actuaries
388 Salem Lake Drive, Suite H
Long Grove, Illinois 60047-6400
Members of the Conference of Consulting Actuaries are also designated as either a Fellow (FCA) or Associate (ACA).