In 2016, the AICPA updated the Statement on Standards for Attestation Engagements No. 16 (SSAE 16) to No. 18 (SSAE 18). This change was made to simplify and converge attestation standards related to SOC 1 audits. SSAE 18 has also expanded to cover more types of attestation reports (including SOC 2), whereas SSAE 16 was limited to only SOC 1 reports.