Keogh plans have minimum eligibility requirements that will probably include most of your employees, but not necessarily all of them. If an employer established a Keogh Plan, eligible employees must be allowed to start a Keogh Plan account as well.

Eligibility requirements include: being over 21 years of age and having worked at least a year as a full-time employee for the employer, where full-time is defined as working over 1,000 hours in a year. Seasonal workers, non-resident alien employees, union employees, and non-working partners or owners in the business can be excluded.

What are Articles of Incorporation?
What are Articles of Partnership?
How Does a 401(k) Compare With Other Retirement Plans?