Background: Patient engagement technologies (PETs) guide patients through perioperative care, but little is known about their costs-benefits. Methods: Retrospective cohort study of patients undergoing elective colorectal, cardiac, thoracic surgery 2015–2020. PET was implemented 2018. Patients were propensity-matched in pre-PET, PET, non-PET groups. Costs of surgical encounter and 30 days post-discharge, mortality, length-of-stay, readmissions, complications, satisfaction were compared. Results: Overall, 4,373 patients underwent surgery and 607 (13.9%) patients enrolled in the PET. PET patients did not have increased costs in any specialty. Colorectal PET patients' variable costs of surgical encounter were $102 lower than non-PET, $1495 lower than pre-PET (p = 0.03). Thoracic PET patients’ total costs of surgical encounter were $9224 lower than non-PET, $2187 lower than pre-PET (p = 0.03). Thoracic PET patients had lower mean LOS (2.4 days, 5.1 non-PET, 3.1 pre-PET, p = 0.03). PET patient satisfaction ranged 86.0%–97.8%. Conclusions: Use of a PET did not increase costs and was associated with benefits for patients undergoing elective surgery.