This is a product designed to protect the investments you have made in yourself and your income earning potential.  You have invested in your education and put in years to get the experience it takes to get where you are.  If you were disabled by an injury or illness and lost your ability earn an income equal to your potential, that would be a great loss on an investment you have made in yourself.

It is important to get these policies through a reputable company, and to get the correct own occupation definition for your situation.  You can get a "true own occupation" (TOO) definition or a "modified own occupation" (MOO)  definition.  A TOO is more expensive than a MOO, but a TOO will allow you to go on claim if you cannot perform the duties of your current profession even if you work at another job. While a MOO is good if you are concerned about a total disability, but you may not be considered disabled if you have the capability to work at another job.  For some people own occupation definition is not a concern, because they feel that it would be have to be a total disability to be unable to perform their job, but for someone like a surgeon where a small injury to their hand could result in an inability to perform their profession a TOO is worth it's weight in gold.

A good DI policy is an important piece of protection in the portfolio of any professional.