Who was the silversmith with AM 900 inside the shield mark on my inherited silver goblets?

The silversmith mark "AM 900" inside a shield typically refers to the maker's initials and indicates that the silver contains 90% purity, which is higher than the standard sterling silver (92.5%). This mark could belong to various silversmiths, but it is commonly associated with artisans from the mid-20th century. To identify the specific silversmith, you may need to consult a hallmark reference or an appraiser who specializes in silver.