

Changing employment status is a qualifying event or whatever it’s called, so assuming the company offers its employees coverage immediately on hiring (not all do), you shouldn’t have to wait for open enrollment. However, while health coverage is a common benefit of employment, it’s not universal and policies vary by employer. That is: ask the company, or if for some reason you don’t want to ask, get a copy of the employee handbook, maybe by asking one of your co-workers for it. The info for the particular company is likely to be in there.
They’ve done that on and off for ages, and the ones being offered with Ubuntu here are mostly pretty expensive or else not so interesting. I’ve been content to buy older Thinkpads and self-install Debian for my past several laptops. I was somewhat tempted by recent Ideapad Yogas but resisted, and since then, prices have gone up, whether due to tariffs or whatever else.