How do i contact secsecu customer service? SECU MD Customer Service Phone Number (410) 487-7328, Email, Address. Loans and Mortgages.What is secsecu md? SECU MD has been open since 1951. It's the largest credit union in Maryland with assets totaling $4.67 Billion and providing banking services to more than 250,000 members. Membership: The credit union is a member-owned financial cooperative providing banking services including savings, loans, and other financial services to members.What are the hours of operation for secu md? Open Today: Lobby Hours: 9:00 am - 3:00 pm Drive-Up Hours: 8:30 am - 5:00 pm HoursPhone Reviews Rating: 3.4 starsbased on 5reviews Write a Review SECU MD has been open since 1951. It's the largest credit union in Maryland with assets totaling $4.38 Billion and providing banking services to more than 252,000 members.