Exhibit 99.39 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-D KEY PERFORMANCE FACTORS April 30, 2000 Expected B Maturity 6/15/06 Blended Coupon 6.3807% Excess Protection Level 3 Month Average 5.77% April, 2000 5.36% March, 2000 5.90% February, 2000 6.05% Cash Yield18.08% Investor Charge Offs 4.70% Base Rate 8.02% Over 30 Day Delinquency 4.72% Seller's Interest10.74% Total Payment Rate13.82% Total Principal Balance$52,271,464,953.72 Investor Participation Amount$500,000,000.00 Seller Participation Amount$5,612,664,435.23