Red bar with MED shows when you will be within 48 hours of the end of the month when your medical is due. For example, if you're due to have your medical updated by end of March, you'll see a red MED bar starting March 30th (the 30th and 31st being 48 hours prior to your drop dead date of end of month).

Remember, you will be dropped from trips if you haven't entered your medical by 0900 LBT the day prior to a trip that extends past the end of the medical due date, or a trip that ends within 48 hours of the medical due date. You should also receive multiple VIPS notifications in your due month explaining this.

I have also heard that you can't put in makeup for a trip in the MED bar until you clear it by entering your medical information. But, I would like one of the gurus here to confirm that to be true or not?