The neonatal cardiac screen is a simple, non-invasive, painless and cost-effective test, with which critical congenital heart disease can be detected in a timely manner. Diseases that can cause serious sequelae or death of newborns, if not diagnosed in time. These malformations require some type of invasive procedure during the first month of life. According to the algorithms published as of 2011, it is performed by measuring pulse oximetry in the right hand and either of the two feet of neonates, with sequential measurements and established cut-off points. In Mexico, in compliance with national and international regulations, the screening has been implemented in some States of the Republic, with its addition as a screening test in the general health law in 2021, which makes it a mandatory study in the Mexican territory. In this document, global background, scientific, technical, operational, regulatory and economic aspects for the proper performance of screening are exposed, also proposing modifications to the algorithm and making known the analysis carried out on the costs and benefits of the Neonatal Cardiac Screen. The objective of making adjustments to the algorithm is to adapt to the demographic conditions of the Mexican population, in such a way that the number of false positives and false negatives related to geographic altitude and the measurement of the perfusion index can be reduced.