Shelf-life of pressure-canned soups - is it still good?
While they are almost certainly very conservative (and with good reason), the FDA recommends that you plan on using home canned goods within one year.  They do not give shelf-life guidelines other than this.

I could not find truly authoritative sources (FDA, a major university extension center) that provided more detail.  Less authoritative sources make various claims, on the order of several years, but I will not quote them or link them here.

A five month old jar is certainly well within year that the FDA guidelines suggest, assuming you followed good canning practices.  The fact that you took the trouble to date the jar is a good indicator of your diligence.