Trends are recurring plan mistakes that IRS Employee Plans sees in audits, voluntary compliance submissions, determination letter applications and annual return filings. These trends are categorized by plan type. Tips on how to find, fix, and avoid common mistakes are available for many of the trends. The earlier you detect and correct a plan mistake, the cheaper it is to fix. Early correction also helps prevent the mistake from affecting other areas of your plan operations. For instance, improperly excluding an employee from the plan for many years could lead to this mistake affecting not only the plan participant, but discrimination testing, top-heavy testing and other plan operations. Plan Type 401(k) Plans 403(b)/457 Plans Defined Benefit Plans Multiemployer Plans SIMPLE IRA Plans SARSEPs Have You Had Your Retirement Plan Check-Up? "Check-Ups" are available to help business owners who sponsor retirement plans develop a better understanding of the requirements for their plans. After reviewing the plan and completing the appropriate check-up, you may find an error in your plan's operation. You may want to correct the error using one of the IRS correction programs. "Check-Ups" involve a three-step approach with the goal of increasing awareness by business owners of the need to operate their retirement plans properly, pointing them to further information and services. Common Plan Mistakes Common Plan Mistakes - How to find and fix common mistakes that happen in retirement plans.