I've been a Certified General Appraiser -- the highest possible State certification -- since 1993.
Appraiser licensing varies from state to state. To participate in any "federally-related transaction," (e.g. a property donation appraisal for the IRS; Federal and State purchases of property or property rights; a bank mortgage), an appraiser
must be licensed or certified by his/her State. The license or certification is evidence that the appraiser has performed at least three years as a trainee under the supervision of a practicing appraiser, has passed a rigorous examination, and completed at least 300 hours of professional appraisal education.
There are three levels of appraiser licensing: Licensed Residential; Certified Residential; and Certified General. A Certified General appraiser holds the highest possible State qualifications. Licensed and certified residential appraisers are prohibited from appraising any properties other than 1-4 family residences and small/non-complex residential investment properties.
As a Certified General Appraiser, I am qualified to to appraise all property types and all property rights.
You should always be sure your appraisal service provider is certified and in good standing. The Appraisal Subcommittee (ASC) of the Federal Financial Institutions Examination Council (FFIEC) maintains a national database of appraisers and their license/certification status. It is available publicly at this link.
Among other things, this database, which relies on reports from each state appraisal board, will tell you if a service provider you are considering has had his or her license suspended, revoked, or whether the certification has lapsed.