Aim: Assess the budget impact of nationwide screening for diminished ovarian reserve (OR), via anti-Müllerian hormone (AMH) levels, to the Portugal National Health System (NHS). Patients & methods: The clinical journey was determined using literature and the family planning decision-making process/response using survey results. A panel of four local clinicians validated all assumptions/inputs. Results: Screening for OR led to an expected savings of € 9.4 million for the NHS, driven by a 24% reduction in medically assisted reproduction (MAR) use. When needed, referral for MAR was earlier and more women used first-line versus second-line techniques. The model estimated a 12% decrease in failure. Conclusion: This model shows AMH screening may allow more informed decisions, leading to a shorter fertility journey, more efficient use of treatments, and substantial cost-savings for the NHS.