Score ham in a diamond pattern, if desired. Place ham in an aluminum foil-lined roasting pan.
Stir together brown sugar, mustard, and orange juice; pour over ham.
Bake at 350° for 1 1/2 to 2 hours or until a meat thermometer inserted into the thickest portion registers 140°, basting ham every 30 minutes with glaze.
Remove ham, and let stand 15 minutes before slicing. Serve with remaining glaze.
Note: For testing purposes only, we used Hormel Cure 81 Famous Boneless Ham.