A maximum out-of-pocket (MOOP) is a cap on the amount of money you have to pay for covered healthcare services in a policy year. Once you reach this limit, your health insurance plan pays 100% of the cost of all covered benefits for the remainder of the policy year. The MOOP protects you from catastrophic healthcare costs, ensuring that you won't have to pay an unlimited amount for medical care in a given year.

Your maximum out-of-pocket generally includes your deductible, copayments, and coinsurance, but does not typically include your monthly premiums, charges for non-covered services, or services from out-of-network providers (unless it's an emergency or your plan has out-of-network benefits that contribute to a separate out-of-network maximum out-of-pocket). The specific amount of the MOOP can vary significantly between different health insurance plans and types of coverage.