What trucks require dot medical card?

ALL vehicles requiring a CDL - that includes both commercial vehicles and combinations with a Gross Vehicle Weight Rating or Gross Combined Weight Rating in excess of 26,000 lbs., as well as vehicles under 26,000 lbs. GVWR which require a CDL because they are a: carrying a quantity of hazmat which requires placards to be displayed or b: a bus designed to transport more than 15 persons (including the driver).

Additionally, commercial vehicles with a GVWR of 10,001 - 26,000 lbs. require a DOT medical card when they're being operated across state lines.