One can go through an educational program and fail to get their medical billing and coding certification. One who sits for the test and has a bit of test anxiety, may jinx themselves into a note so favorable grade. The test requires that the applicant pass with a 70% or better. It may seem very lenient, but there are some candidates that are very well prepared, but still do not do well in taking tests. The good news is that, within a short amount of time, one can retest.
There are students that have a lot of the information from going to school and just choose to work in the field without certification. They know what they are doing and can complete the jobs with excellence, all that they are lacking is the certificate. And at times, they go back to retake the test, after many hours of performing the job with confidence.