Our church always celebrates a 9:00 AM mass on civic holidays: Memorial Day, Independence Day, Labor Day, and Thanksgiving Day. There are special masses for Independence Day (and other civic observances), Labor Day (For the Blessing of Man’s Labor), and Thanksgiving Day. There is no specific mass for Memorial Day as such.
My priest usually uses the mass prayers from Independence Day (and other civic observances) and then uses the current weekday mass readings for that day. This year Memorial Day will fall on Monday of the 8th week in Ordinary Time. Ordinary Time actually resumes on this day because the Easter Season ends the day before on Pentecost.