Health insurance to cover gap before new job starts

I am asking for my son – I am trying to help him deal with the maze of health insurance coverage. But I am having trouble figuring out a solution here.

tl;dr: My son needs health insurance to cover the gap between the time when he moves to another state and the start date of the job he has landed in that state – a period of a few weeks. I have been completely unable to figure out a way for him to have health insurance coverage during that time.

My son, who has been unemployed since finishing up a grad school program, has been on private health insurance in the state where he lives. He will be starting a job in another state sometime in August (probably 8/11). He has found an apartment in the city where his new job is, and will be moving in there on 7/25.

The Problem: his current health insurance applies only in the state where he currently lives, and will end when he moves out of state. So he needs to find health insurance coverage in the new state to cover the few weeks gap between when he moves there and when his job starts.

I have looked at short-term insurance, but it seems he cannot get that kind of coverage because he takes medication for a mood disorder. As to the ACA exchange in his new state, my understanding is that if he applies, under the special enrollment period due to his move from one state to another, his coverage will not start until the beginning of August or perhaps September.

So what to do? Does he really have to go without health insurance for the few weeks before his work insurance kicks in? And if so, what happens if he needs expensive health care (e.g., hospitalization for injuries from an accident) in that period? Is that how people go bankrupt? Or am I just not understanding how this all works and missing some obvious solution here?

Sorry for the long post! I couldn’t figure out what I could leave out . . .