Few. Most require or prefer you to be 21-years-old or older for insurance reason. I know Rural/Metro will hire people under 21.
https://careers-rmetro.icims.com/jo...hLocation=-12789-San+Jose&searchCategory=8723
Just FYI, if you get hired at Rural/Metro Milpitas (aka Rural/Metro IFT), you will literally hurt your chances to work for County Ambulance (operated by Rural/Metro) if you want to do 911 in Santa Clara County. You are required to work IFT for >1 year before being allowed to interview for a 911 position when opened, and you will be given no preference over other candidates with no experience or who work at other companies. You will not be able to just "lateral" over, and you won't be putting your foot in the door by getting hired by them. From what I am told, they should be giving people that disclaimer in interviews, but I dunno. You will get experience though, and there are ALS (non 911), CCT, and NICU/PICU shifts. People complain about the pay, but I think the pay is actually is about normal for IFT-only ambulance companies (starting pay no experience is $11.50/hour I believe). They have 8, 10, and 12 hour shifts, you do get over time after 8 hours and double time after 12 hours. Rural/Metro IFT has a union, United EMS Workers (AFSCME local 4911), but no collective bargaining agreement (CBA)/contract yet.
American Medical Response (AMR) used to hire under 21. Closes location I know of is San Mateo, Concord, and San Francisco. Doesn't look like they are hiring anywhere in the San Francisco Bay Area right now.
https://career4.successfactors.com/career?company=EMSC
Depending on location, union could be NEMSA or United EMS Workers/AFCSME. I believe their pay is one of the highest regardless of doing IFT or 911. I've been told random starting pay though (I've heard of $16/hour to $19/hour for EMT). After 6 months, you can start picking up ALS (911) shifts
if available.
When I first became an EMT, I was 20-years-old. Most companies (eg NorCal Ambulance, Royal Ambulance) turned me away because I was under 21.