Generally speaking, you get 2 - 3 years after manufacture till expiration date. After expiration date, you might get an extra 5 years on injectables, with a recommendation to try to use them in a 1-3 year period. These are informal recommendations gleaned from various medical readings on the subject. Tablets have a longer shelf life, with some lasting up to 15 years past expiration.
Expect some degradation occurring in the years after expiration.