Are you asking on behalf of yourself?
Yes i need help understanding self-certification
To be in compliance with federal regulations, all commercial drivers are required to certify to the DMV the type of driving they perform or expect to perform. If you self-certify to a non-excepted driving type NA or NI are also requited to submit a copy of their USDOT Medical Examiners Certificate.
Does this make my driving legal?
Yes this will satisfy the new federal regulations
What happens if my Medical Examiners Certificate expires before i replace it with a new one?
To avoid your status and license from being downgraded it is important to keep your information up to date and not allow it to expire.
What are the requirements for working for a private company that provides bus service to a local school system?
It is acceptable to choose El
How can i be sure that the DMV has received the necessary paperwork from me to drive types NI and NA?
If the DMV has received the required paperwork your medical certification status will be "certified". Otherwise your status will be considered "not certified"
Can i keep my CDL but with restrictions on it?