Exhibit 99.20 MBNA MASTER CREDIT CARD TRUST II SERIES 1996-M KEY PERFORMANCE FACTORS SEPTEMBER, 1999 Expected B Maturity 12/15/06 Blended Coupon 5.6389% Excess Protection Level 3 Month Average 5.93% September, 1999 5.79% August, 1999 5.77% July, 1999 6.25% Cash Yield 18.03% Investor Charge Offs 4.60% Base Rate 7.64% Over 30 Day Delinquency 4.90% Seller's Interest 6.99% Total Payment Rate 14.16% Total Principal Balance $ 45,780,732,257.76 Investor Participation Amount $ 500,000,000.00 Seller Participation Amount $ 3,198,912,739.27