OBJECTIVES: Sentinel lymph node biopsy (SLNB) may be considered in the setting of a pre-operative diagnosis of endometrial intraepithelial neoplasia (EIN) due to high rates of concurrent invasive cancer. The aim of this study is to compare the cost-effectiveness of different surgical management strategies for a pre-operative diagnosis of EIN. METHODS: A decision model was developed from a third party payer perspective to compare four surgical strategies for the management of EIN: (1) hysterectomy; (2) hysterectomy with frozen section (hysterectomy + frozen); (3) hysterectomy with SLNB (hysterectomy + SLNB); (4) hysterectomy with frozen section and SLNB (hysterectomy + frozen + SLNB). The probability that frozen section identifies high- or low-risk cancer, final pathology distribution, adjuvant treatments, and surgery/imaging costs were abstracted from the literature, Medicare reimbursement data, and the financial department of a private academic hospital. Adjuvant treatments were determined through NCCN guidelines and published studies. Effectiveness was quantified as percentage of patients who received the guideline-based treatment that aligned with their true stage. RESULTS: The base case cost and effectiveness of each strategy was: hysterectomy-$4383/89%, hysterectomy + frozen-$5220/99.2%, hysterectomy + SLNB-$5354/94.7% and hysterectomy + frozen + SLNB-$5938/99.6%. Hysterectomy + frozen had an incremental cost effectiveness ratio of $8111 per patient who received adjuvant treatment that aligned with true stage compared to hysterectomy. Hysterectomy + frozen + SLNB had an ICER of $168,171 per additional patient who received adjuvant treatment that aligned with their true stage compared to hysterectomy + frozen. CONCLUSION: Hysterectomy + frozen + SLNB is a costly strategy for pre-operative EIN when compared to hysterectomy + frozen, with limited clinical benefit. Hysterectomy with frozen section and subsequent intraoperative staging decisions should continue to be standard of care.