BACKGROUND: Literature evaluating the management of abnormal uterine bleeding in premenopausal patients prior to endometrial malignancy diagnosis is lacking. OBJECTIVE: To evaluate predictors and consequences of inadequate evaluation and management of abnormal uterine bleeding and time to endometrial sampling in premenopausal patients prior to endometrial malignancy diagnosis.Study Design.This was a retrospective cohort study of premenopausal individuals with endometrioid endometrial cancer or atypical hyperplasia at a single institution from 2015 to 2020.. Complete noninvasive management encompassed pelvic exam, ultrasound, and progestin treatment before or in conjunction with the endometrial sampling of diagnosis. Multivariable logistic and ordinal odds models were used to evaluate predictors and outcomes. RESULTS: 152 subjects were included, 80.3 % with cancer and 19.7 % with atypical hyperplasia. The majority of patients had anovulatory bleeding, obesityand recent health care. Only 20.4 % had complete nonvinvasive management, and only 12.5 % had complete noninvasive management or endometrial sampling within 2 months of presentation with abnormal bleeding. Class III obesity reduced the likelihood of complete assessment and increased time to sampling, while age 45 and up and parity reduced time to sampling. Most patients had partial workup but no progestin treatment and long intervals before endometrial sampling after presentation to a provider with abnormal bleeding. Incomplete workup correlated to worse cancer grade and stage. CONCLUSION: Despite high clinical risk and health care contact, most patients had insufficient gynecologic management preceding a diagnosis of endometrial malignancy. Inadequate care correlated to worse oncologic outcomes and demonstrates missed opportunities for early detection and prevention of endometrial cancer.