A Keogh plan will primarily need a plan document and a way to invest. A Keogh plan can be established by any self-employed individual of a sole proprietorship, partnership, and Limited Liability Company (LLC).
A plan document must be put together by the sponsor, or the standard plan document from a prototype plan at a broker-dealer or trustee institution can be used. It is not necessary to submit the document to the IRS, but if you have any employees, it is required that you use this document and any other printed information necessary to fully explain and disclose their rights in regards to the plan.
If requested in writing, the IRS will evaluate a plan document and give them a letter of determination, which will explain if the plan has correctly implemented the relevant statues or not. For larger employers they will charge a fee for this service, but employers with fewer than 100 employees can receive a letter of determination at no cost.
Some plans will fall into a safe harbor category which will make their paperwork minimal or nonexistent. Individual 401(k)s, which are a type of profit-sharing Keogh for sole proprietors, must only file a 5500-EZ if their assets accumulate to over $250,000, and the form takes but a few minutes to fill out.
More complicated plans, that involve more employees or perhaps defined benefit components, will require more effort and professional help.
If I Want to Establish a Keogh Plan, Do I Have to Establish One for All Employees of My Business?
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What are Articles of Partnership?
How Does a 401(k) Compare With Other Retirement Plans?