I have encountered several sources now writing the 'B' or 'M' in lowercase, like...
A bachelor's degree is an undergraduate university degree.
...whereas in the past I more often read Bachelor's / Master's degree
and also was told once that it should be capitalized.
Is this maybe just a matter of context?
It appears to me that most people write it in lowercase when writing about the topic in general. However, if you try to express something like...
I have received my Master's degree in Business Administration at...
...you are talking about your degree and I often see people capitalizing it then.