<![CDATA[Background: Exclusive breastfeeding coverage globally and nationally has not yet reached optimal targets. A major obstacle faced by postpartum mothers is insufficient early milk expression, which is closely linked to inadequate stimulation of prolactin and oxytocin hormones. Non-pharmacological methods, particularly manual expression techniques, offer accessible options to overcome this lactation barrier. Purpose: To determine the effect of the Marmet Technique on the transition of breast milk expression levels among breastfeeding mothers. Method: A quantitative quasi-experimental study with a one-group pretest-posttest design was conducted in the service area of Indralaya Community Health Center. A sample of 33 breastfeeding mothers experiencing lactation insufficiency was selected via purposive sampling. Data collection utilized a validated breast milk flow questionnaire (24 items, Cronbach's Alpha = 0.745) administered before and after a 7-day intervention. Data were statistically analyzed using the Marginal Homogeneity Test. Results: Prior to the intervention, 97.0% of respondents experienced poor milk expression. Following the consistent application of the Marmet Technique, 90.9% shifted to the smooth expression category, and 9.1% achieved moderate expression, leaving 0% in the poor category. The statistical analysis showed a significant shift in lactation levels with a p-value = 0.000 (z = 5.660). Conclusion: The application of the Marmet Technique produces a statistically significant improvement in the level of breast milk expression among breastfeeding mothers, supporting its integration into routine postpartum nursing care plans. Keywords: Breastfeeding Mothers; Breast Milk Expression; Lactation Care; Marmet Technique.]]>
