B4155 HCPCS - ENTERAL FORMULA, NUTRITIONALLY INCOMPLETE/MODULAR NUTRIENTS, INCLUDES SPECIFIC NUTRIENTS, CARBOHYDRATES (E.G., GLUCOSE POLYMERS), PROTEINS/AMINO ACIDS (E.G., GLUTAMINE, ARGININE), FAT (E.G., MEDIUM CHAIN TRIGLYCERIDES) OR COMBINATION, ADMINISTERED THROUGH AN ENTERAL FEEDING TUBE, 100 CALORIES = 1 UNIT