Lengkepan kalimah di handap ieu: Republic Records dikonfirmasi dina April 2015 yén remix tina "Bad Blood" bakal ngawula salaku single kaopat ti "1989". Vérsi remix anu dipirig ku rapper Kendrick Lamar dileupaskeun dina 17 Méi 2015, pikeun diunduh digital ku Big Machine Records. Rilis single ieu dirojong ku perdana video musik na di
2015 "Billboard" Music Awards. "Bad Blood" mangaruhan radio hit kontémporér AS dina 19 Méi 2015, dina Big Machine and Republic Records imprint. Lagu ieu dirilis ka radio hit kontemporer Italia dina 12 Juni 2015, ngaliwatan Universal Music Group.