It's not a prefix in the context in which you're using it. It's merely spelling a word incorrectly based on how some people say it. It has zero semantic value. It is completely unrelated to the prefix a which just means without.
For example the median expected annual pay for a typical Medical Records Technician in the United States is $32,140 so 50% of the people who perform the job of Medical Records Technician in the United States are expected to make less than $32,140.
The U.S. Bureau of Labor Statistics reports that the median annual salary for health information technicians (including medical coding specialists) is $35,900. The lowest paid 10% earn less than $22,700 while the highest paid 10% earn more than $57,320.