As a plan sponsor you may be required to engage a CPA firm to perform an audit of your 401(k) plan. As a general rule, the audited financial statements are required to be filed with your Form 5500 if you have 120 or more eligible employees. This is the general rule and your specific situation would need to be evaluated to make a final determination. The audit process can seem daunting if you have never been through the process. At Iyer Associates, you can be assured of the best service at the most cost effective price.