A Simplified Employee Pension IRA is indeed a simple retirement plan, In fact the sep ira simpler than the simple ira. It is a plan ideally suited for self employed people. There are no real administration costs involved if you are self-employed and don't have employees. In case you have employees, they all receive the same benefits under this plan. SEP accounts are treated as IRAs. So, funds can be invested the same way as any other IRA.