An M visa is a nonimmigrant visa for nonacademic or vocational studies. To hold an M-1 visa, you cannot enter as a general student, meaning that you must be involved in a ‘full course of study’. The visa is issued by the US Department of State after you have been accepted to study at a community or junior college, post-secondary vocational school, or post-secondary business school, with at least 12 semester or quarter hours. To hold an M-2 visa, you must be a dependent of an M-1 visa holder.
M visas for new students can be issued up to 120 days in advance of the start date for a course of study. However, you will not be allowed to enter the United States on your student visa more than 30 days before the start date.
If you are on an M-1 visa, you are not required by the rules of your visa to be covered by health insurance. That being said, most schools will require you to have adequate insurance coverage for the entirety of your studies.
It is important to ensure you have health insurance, not only to become compliant with the rules of your vocational program, but also so you do not end up with extremely high medical bills in the case that your health is compromised. There are three likely options that will decide what health insurance you purchase: