Insurance question

My husbands leaving his job due to his unhappiness there and going to work elsewhere. He’s planning on leaving his job after he gets a set new job in April ish. I’m covered under his insurance but planning on switching over to a new insurance with baby after he leaves his job. My question is: is it possible to apply for insurance in mid April, or year round?

I’m clueless when it comes to insurance but I thought there was a only a certain time where you can apply for insurance 👀