Breakfast sausage is usually good in the refrigerator for 5 to 7 days but it's best to eat the breakfast sausage within a few days of refrigerating it.
When frozen the breakfast sausage should last for 6 months to a year.
The breakfast sausage lasts longer frozen but it's still best to eat the breakfast sausage within a few months for the best taste and freshness.
The freezing of the breakfast sausage helps keep bacteria off the sausage so that it lasts longer.
But in the refrigerator it can't keep the sausage cold enough to keep the bacteria off the sausage long enough.
I've kept breakfast sausage in the freezer for a year and it was just fine.