All assessors employed in Minnesota are required to hold one of four levels of licensure (CMA-Certified Minnesota Assessor, the minimum level; CMAS-Certified Minnesota Assessor Specialist, the second level; AMA-Accredited Minnesota Assessor, the third level; and SAMA-Senior Accredited Minnesota Assessor, the highest level) issued by the State Board of Assessors. The complexity of area taxing districts and the total market valuation in several classes of property determine which licensure level is required. The authority to value income-producing properties is also restricted by law to only licensed assessors who have successfully completed at least two income classes. Extensive course work, written exams, oral exams, and/or the presentation of form or narrative appraisals along with required years of experience in the field must be satisfactorily accomplished by these individuals seeking licensure. Additionally, assessors must satisfy the established requirements for continuing education every four years to maintain their current licenses.