I have been researching, but help me understand this a little better. We will be in DC for 5 days and I think the short pass would work 4 of us and regular cards for the 2 seniors. Nearly all of our trips will to/from King St to major sites which are most all under $3.50. I don't see a way online to get just the $2 card and pass mailed to us ahead of time, but as I understand it I can get just the $2 card at the Transit Shop near our hotel and then add the 7 day online (have to go there anyway to get 2 senior cards).

So my question is there a minimum amount I can put on each card for overages? We are going to take a few trips that are like $3.55. My guess is each person will have like .20 cents of overage for the week. If I have to put a bunch of credit on each card the short pass starts to not make as much sense.