A. A sub-limit is the cap on the sum insured for a defined procedure or condition. Capping room rent is a common example of a sub-limit. Here, the insurer sets a cap on the room rent. If the customer chooses a very expensive room, then the customer pays the amount that exceeds the cap. This can turn out to be expensive because certain expenses such as the doctor’s fees and surgery costs are linked to the category of the room that a customer chooses. So a sub-limit on room rent means the customer will end up paying not only the difference in room rent but also other associated costs.