Its been awhile since I had to deal with this, so verify anything important.

Essentially you are dealing with three types of insurance.There is LongTerm Disability (LTD) and LongTerm Care (LTC) and Social Security Disability Income (SSDI). You haven't mentioned LTC but you might check with your employer. Get it if they offer it.

LTD comes in a couple of flavors. The best replaces lost wages for the rest of your life at 80% and starts when you can no longer do your professional duties as an engineer.

The worst ones will require you to stage an armed confrontation at their office in order to get a dime.

OK, that last is exaggerated but not by as much as you think. There are some real scumbags in this area. If your employer is big enough then you will probably be alright.

However, even the decent ones often pay you until you start getting an SSDI check. Then, since SSDI pays you "backpay" for the months and months you waited, the insurance company expects you to reimburse them for what they paid you!

When you file for SSDI (ASAP BTW) it will drag on forever. Months and even years. It is insane. The best thing that I did was to wait four months so that the first hoops had been gone through and my application was sitting on some bureaucrat's desk. Then I called the local office of my congress critter. Local is important because that is what they are there for. I explained that I was not asking him to intervene in any decisions but that I was hoping that he could help with the red tape.

A few days later I got a call from a bureaucrat apologizing for the delay and a couple of weeks later a check showed up.

Democracy in action!