What makes me technically an ’employer’?

Q: “I am a sole owner of a medical practice and (excluding myself) currently have one employee. I would like to know how Pennsylvania’s definition of an employer as “any person employing four or more individuals within Pennsylvania” impacts me. I would also add that I previously employed three other people who are no longer with the practice. If I do not meet the definition of employer in Pa., what is my status?” – Valerie, Pennsylvania