Effective January 1, 2004, the GAO has deleted taxation from the list of subjects that always satisfy the 80-hours every two years requirement.
Instruction in topics that may meet CPE requirements of licensing bodies or professional organizations no longer automatically satisfy the 80-hour CPE requirement. Any CPE for GAGAS must be in subjects that "directly enhance the auditor's professional proficiency to perform audits and/or attestation engagements."
Most tax services are not related to the subject matter of audits performed under GAGAS and therefore do not qualify for satisfying GAGAS requirements. There are some exceptions if taxation relates to an objective of an audit conducted under GAGAS. You must clearly document the rationale for including such taxation training as part of your GAGAS CPE requirement.