Smoked ham may or may not be fully cooked. Ham purchased in vacuum-sealed federally inspected packages, canned hams and spiral-sliced hams are all fully cooked and safe to eat cold right out of the package (although some people may prefer to cook them long enough to warm the ham). If you are unsure of the status of your smoked ham, then heating the ham until the internal temperature reaches 160 degrees will ensure that it is safe to eat.
Things You'll Need
Determine if the smoked ham has been fully cooked prior to sale. According to the USDA, ham which has not been fully cooked should indicate this clearly on the packaging and the words "cook thoroughly" must be prominently displayed on the label.
Ensure that the ham is properly defrosted. If the smoked ham is still frozen, it will take approximately 1.5 times longer to cook. Smoked ham can be defrosted in the refrigerator for up to five days before cooking.
Set oven temperature to 325 degrees for both cooked and uncooked hams.
Determine the weight of the ham. This will be marked on the packaging, or the ham can be weighed on a scale.
Cook the ham. Smoked ham indicating that it needs to be cooked thoroughly will require the following minutes of cooking time per pound of ham: whole, bone-in ham: 18 to 20 minutes; half, bone-in ham: 22 to 25 minutes; shank or butt portion, bone-in: 35 to 40 minutes; arm picnic shoulder, boneless: 30 to 35 minutes; shoulder roll or butt, boneless: 35 to 40 minutes.
Warm up cooked ham. Cooked ham requires less time as it only needs to be reheated. In order to reheat ham, estimate the following minutes of cooking time per pound of ham: whole, bone in ham: 15 to 18 minutes; half, bone in ham: 18 to 24 minutes; arm picnic shoulder, boneless: 25 to 30 minutes; canned ham, boneless: 15 to 20 minutes; vacuum-packed ham, boneless: 10 to 15 minutes; spiral-cut ham: 10 to 18 minutes.
Check the ham's temperature occasionally while cooking by inserting a meat thermometer into the ham. Be careful not to touch one of the ham bones with the thermometer as it could affect the reading. The ham will be done at 160 degrees.