My 186 form is expiring, so I will need to resubmit the 186 form. Do I have to contact the medical school in my county again like what I did for the first time 5 years ago, or I can figure out this 186 form in the U.S.? Thanks.

NO. you can download the form 186 from the ECFMG site and print it. Attach a new passport pic and go to any place that will attest that is you in the picture. Sign the form at the bottom in front of attesting officer and they will sign it and you just send that form.