There is one way that accreditation is highly important: if you receive a degree from an alternative source, such as online distance learning. When it comes to a traditional college, name recognition may be more important than accreditation. While most brick and mortar schools are accredited, some colleges have a greater impact than others.
Everyone knows that Harvard is an elite school. It plainly looks better on your resume no matter what profession you may be entering—medical, engineer, computer, etc. Name recognition also depends on the field of study. Some colleges have a better known and more well respected program in a specific field than others. Harvard may be the king of colleges, but there are a number of good departments in colleges throughout the country. Apart from accreditation, getting a degree from a good department can be as helpful in the job market as getting a degree from an Ivy League school. For these top schools accreditation is implied. There is no need for a potential employer to investigate the college's accreditation. In this sense, accreditation is not nearly as important in top universities than it is in smaller colleges or online universities.
Accreditation is proof that the college has given out a quality education. In the case of distance learning programs, there are non-accredited colleges that will give out a degree for little to no coursework. Really, students are just buying the diploma. If you are using such a degree to apply to a graduate program, these types of degrees may not even be recognized. The same goes for applying for a job.
Accreditation is a peer review process in which institutions of higher learning assess each other's educational standards. There are also accrediting institutions, such as the Middle States Association of Colleges and Schools, which overseas schools in a particular region.
If you are applying within a particular program it is important to check the department's accreditation. Do not assume that just because a school has been accredited that each department is accredited as well. In many cases, a school's accreditation applies to every department. In other cases, accreditation is granted on a department-by-department basis. So it is recommended that you not only apply to an accredited school, but that your department of study is accredited.
To further confuse the issue, there are colleges that claim accreditation when in fact the school is not. Just as there are online colleges that administer fake diplomas, there are also less-than-reputable accrediting boards that give out false accreditation. A school must be accredited by a board recognized by the U.S. Department of Education.
What it comes down to is this: accreditation is important according to type of career you will be entering and the type of college where you are getting your degree. If there is some question about a college's accreditation, it is important to be able to show an employer that your degree comes from an accredited institution or program. It is not enough that you have good grades, the college itself needs to have a good grade as well.