Provided herein are biodegradable poly(ester amide) elastomers, methods of making the elastomers, and methods of using the elastomers, for example for tissue engineering. The elastomers can be used for preparation of tissue prostheses, such as a heart valve leaflet, a heart valve, cartilage, myocardium, blood vessels, smooth muscle, skeletal muscle, or other tissues. Also provided herein are semiquantitative FTIR methods for determining structure of a poly(ester amide) elastomer.