A Practice Note discussing the requirements for occasional notices based on plan events for defined contribution plans under the Internal Revenue Code (Code) and the Employee Retirement Income Security Act of 1974 (ERISA) and accompanying regulations. This Note provides an overview of the 401(k) plan safe harbor notices, the 404(c) notice, the blackout notice, the notice of amendment significantly reducing the rate of future benefit accruals (204(h) notice), the notice of election to remain on prior vesting schedule, the notice to interested parties, and the summary of material modification (SMM).