Photo identification (e.g. driving licence, passport);
4 photographs which meet Department of State requirements;
For applicants aged 16 and over, a UK police certificate (known as an ACRO) issued within the past 24 months;
Vaccination records, which can be obtained from your regular healthcare provider. If you are unable to obtain your vaccination record, you should consult with the panel physician at the time of your appointment. The vaccination chart is available here, as a PDF (187Kb);
Completed medical questionnaire, which can be downloaded here, as a PDF (1 page).
I assume for the Medical they are looking for DUIs ot Drug related crimes even though they ask for that information anyway. The date of the medical determines the expiration of the visa.