A Practice Note reviewing the rules governing pre-approved tax-qualified retirement plans, which are classified under IRS guidance in Revenue Procedure 2017-41 as either standardized or nonstandardized plans. Pre-approved plans were previously classified as master, prototype, and volume submitter plans. This Note addresses how adopting employers may rely on these plans for tax-qualification purposes under the Internal Revenue Code and when employers are eligible to apply for their own individual determination letters. It also provides best practice tips for employers to complete the adoption agreement or select appropriate provisions for a pre-approved plan.