Health insurance deductibles seem like an odd feature of insurance. Your provider is going to pay most expenses, and your deductible may wind up a mere fraction of the total costs. How is paying a deductible supposed to help cover your medical care? Ultimately, it can be regarded as something of a symbolic gesture on your part.
There are many other contributing factors to the existence of the health insurance deductible. By sharing some of the cost with the customer, the financial stress of a sudden, catastrophic medical expense may be dampened, for instance. But the core reasoning on the part of your insurer essentially comes down to this: With a deductible required on your part, the likelihood of frivolous medical expenses may be reduced. You may not be covering the entire bill, but a deductible will prevent a customer from regarding their health coverage as "free doctor visits."
Fortunately, what you pay in deductibles will be limited by an out-of-pocket maximum. We've all heard of cancer treatments and extensive surgeries racking up seven-figure bills. For the average American, paying even a fraction of a million-dollar hospital bill is simply an impossible task. Medical costs can be astronomical, and it is not reasonable to expect that many of us are able to cover them on our own, or even with help. So, the out-of-pocket maximum helps to ensure that someone with proper coverage will not be personally bankrupted simply because they had the bad fortune to get sick.
Health insurance deductibles help to subtly regulate how health insurance is used. By cutting down on frivolous use of healthcare, your insurer — and your medical care providers — have more resources to expend when it counts.