Get rid of bureaucratic bullshit and you'd get > 250 billion $ a year [1]. Get rid of insurances and other middlemen and you'd get another 450 billion $ a year by going for single-payer [2]. Then, get the homeless enrolled in insurance as well - even if the government pays the premium, every single homeless person costs > 18k a year in ER visits [3], a lot of which could be prevented if these people could go to a doctor before they'd be sick enough to incur serious ER costs. And finally, get as many homeless drug addicts back into some sort of stable housing. A lot of drug usage "on the streets" is self-medication to cope with the immense stress that comes from being homeless. Yes, there will always be a certain percentage of hardcore voluntary homeless people, but that's way better manageable than the status quo.

That should be way more than enough to hire enough nurses.

[1] https://www.americanprogress.org/article/excess-administrati...

[2] https://ysph.yale.edu/news-article/yale-study-more-than-3350...

[3] https://www.newsweek.com/homeless-americans-are-costing-us-m...