Much depends upon what it is doing now. Plums are usually on big trees so I'm not sure how a miniature would behave. Are the leaves green? Scrape a little bit of bark off with your nail and see if the wood underneath is green/white or brown. If it is brown then the tree is dead - but you didn't say the leaves were gone, only the buds
Young trees struggle when the frosts are late, so your plum may just have got it's buds frosted, or at leat very cold, and so they died off. If the tree otherwise looks healthy, then give it some TLC this year, and hopefully it will try again next season.
Do you have it in a pot or in the ground? Do you feed and water it regularly, or doesn't it need the water due to your weather? Maybe a bit more detail as to its condition now?