I recently started with JetBlue, and the benefits package is great.
However, my new employer only offers one option for health insurance. And, unfortunately, the pediatrician my kids have been seeing for years does not accept this new insurance. So, now I have to choose whether to pay out of pocket to continue to use him, or find a new pediatrician. You may run into a problem like this.
Also, before I started at JetBlue, my son had minor surgery scheduled for a date after my start date. After looking into my benefits package, I found out that the new insurance wouldn't cover this surgery (due to it being a pre-existing condition, I presume). So, we had to move his surgery forward to a date when my family was still covered by our previous insurance. He wasn't exactly in an extended treatment program, but it is a similar situation.
Lastly, there is one other thing to watch out for. My JetBlue start date was October 7th. Before showing up for class, I had assumed that my health benefits would be effective on my start date, as they had been at my previous employer. After I showed up, I found out that the health benefits were not in effect until the first day of the following month (November 1st).
This could have bitten me in the a$$, because I had almost cancelled my previous insurance (a continuation of my USAirways plan, paid for by ALPA) effective on October 7th. Luckily, I had waited until I actually started at JetBlue to cancel my other insurance. Don't assume any new insurance will start coincident with your employment start date.
Do you have a new job lined up, CCDiscoB?