Exhibit 99.42 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-D KEY PERFORMANCE FACTORS June 30, 1999 Expected B Maturity 6/15/2006 Blended Coupon 5.3714% Excess Protection Level 3 Month Average 4.07% June, 1999 4.07% May, 1999 N/A April, 1999 N/A Cash Yield17.91% Investor Charge Offs 3.77% Base Rate10.06% Over 30 Day Delinquency 4.82% Seller's Interest11.01% Total Payment Rate13.71% Total Principal Balance$44,380,968,357.42 Investor Participation Amount$500,000,000.00 Seller Participation Amount$4,888,448,838.93 For purposes of calculating the Base Rate and Excess Protection Level, a Coupon of 8.06% (28/360) was used. The Base Rate was calculated using a 28 day monthly period, 6/3/1999 - 6/30/1999.