Magnesium alloysMagnesium alloy are biodegradable in the human body; however, they have poor corrosion resistanceCorrosion resistance. The addition of rare earthRare-earth elements is an innovative method to improve the properties of magnesium alloysMagnesium alloy for biomedical implants. The effect of cerium in magnesium alloysMagnesium alloy must be studied to determine its effectiveness in increasing corrosion resistanceCorrosion resistance. Alloys based on the Mg-Zn-Ca system with various compositions of Ce were melted and cast. Additionally, pure Mg samples coated with polymersPolymer (polycaprolactone, polylactic acid, and polyhydroxyalkanoates) combined with graphene were assessed for additional corrosionCorrosion protection. Optical and scanning electron microscopy was conducted to characterize the coatings for their adherence to the magnesiumMagnesium samples. Compression testing resulted in a maximum average ultimate tensile strengthStrength of up to 312 MPa and a maximum average yield strengthStrength of 261 MPa. When immersed in Ringer’s solution, the magnesium alloysMagnesium alloy with 0.2 wt.% Ce showed the lowest amount of weight loss of 11%. It was determined that samples with up to 0.2 wt.% Ce had the highest corrosion resistanceCorrosion resistance. UncoatedMg Mg alloys containing Ce with Zn and Ca as well as polymerPolymer coated pure Mg show potential for suitable biomedical implant materials.