A high sum insured does not always guarantee that the entire hospital bill will be paid. One reason is the “reasonable and customary charges” clause commonly found in health insurance policies. Under this provision, insurers can look at whether the amount charged for a treatment or medical service is broadly in line with what is usually charged for similar treatment in that location. The issue often arises when a hospital’s charges are far higher than what other comparable hospitals charge. In such cases, even if the treatment is covered and there is enough sum insured available, a part of the bill may still be left for the policyholder to pay.