Their website lists a number from which you can purchase accessible seating. They also provide a host of other amenities you may be interested in given your father's needs. See: https://www.mlb.com/nationals/ballpark/disability-access-guide
Information you've received thus far is correct. You guys will have a blast.
They have plenty of sections for those in a wheelchair. But yes you do need to get those tickets.they have wheelchair accessibility everywhere, entrances, parking spaces. But yes you do need to get a ticket in that section.
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