SSARS No. 21 codified and clarified all previous SSARS standards and was effective for financial statements ending on or after December 15, 2015. It revised existing standards, upgraded service requirements, and introduced a new level of service—the “Preparation Engagement.” SSARS No. 21 requires numerous practice issues for the various service levels, including confirming the services to be provided to the client, attest vs. non-attest services, required procedures to be performed and documentation of them, and reporting requirements for each level of service. SSARS No. 21 also addresses specific issues overlooked in the original standard. Updates to SAS No. 21 are also provided and discussed.