Returns for calendar-year retirement plans are due today. The IRS lists the form to file, where to file, and how to obtain an extension. One-person plans may be exempt from filing if total assets at year-end don’t exceed $250,000 (provided it’s not the final plan year). The forms have been updated, so look for new required information. No returns are required for SEPs and SIMPLE-IRAs. #IdeaoftheDay