Many health insurance policies have a certain capping on per day room rent either limited to a category or as a percentage of Sum Insured. When you avail a room, higher than the eligible category or limit, a proportionate deduction is applied to the overall treatment expenses ie., the overall claim amount will be reduced as a proportion of difference between the eligible and the availed room cost. Only the cost of medicines which are sold at MRP are paid in actuals.
For example, if your room rent limit is 3000 and you opt for a room rent of 4000, then if your overall claim is 1,00,000, the insurance company will pay only 75,000 considering the ratio in which the room rent limit was exceeded. This is called the proportionate deduction under the terms and conditions of a health insurance policy.