Exhibit 99.21 MBNA MASTER CREDIT CARD TRUST II SERIES 1996-K KEY PERFORMANCE FACTORS April 30, 1998 Expected B Maturity 11/17/03 Blended Coupon 5.8380% Excess Protection Level 3 Month Average 5.44% April, 1998 5.86% March, 1998 5.79% February, 1998 4.67% Cash Yield 18.66% Investor Charge Offs 4.96% Base Rate 7.84% Over 35 Day Delinquency 5.03% Seller's Interest 14.63% Total Payment Rate 14.61% Total Principal Balance $35,947,972,379.88 Investor Participation Amount $1,000,000,000.00 Seller Participation Amount $5,259,577,861.39