Premium: Monthly payment to maintain coverage, regardless of whether you use services. Like a subscription fee.

Deductible: Amount you pay out of pocket before insurance starts sharing costs. Example: $2,000 deductible means you pay the first $2,000. Some services (preventive care) are covered before meeting the deductible.

Copayment (Copay): Fixed dollar amount for a specific service. Example: $30 for primary care, $50 for specialist. Paid at time of service.

Coinsurance: Your percentage share AFTER meeting the deductible. Example: 20% coinsurance = you pay 20%, plan pays 80%. Continues until you hit OOP max.

Out-of-Pocket Maximum (OOP Max): The most you'll pay for covered in-network services in a year. After this, plan pays 100%. Includes deductibles, copays, coinsurance. Does NOT include premiums or out-of-network costs.

In-Network vs Out-of-Network: In-network providers agreed to negotiated rates (you pay less). Out-of-network haven't — you may pay much more. Many plans have separate, higher deductibles and OOP max for out-of-network.

Prior Authorization: Insurer approval required BEFORE certain services. Without it, your claim may be denied even if normally covered.

Explanation of Benefits (EOB): Statement from insurer after processing a claim. Shows what was billed, what they paid, what you owe. It is NOT a bill.

Formulary: List of covered prescription drugs organized in cost tiers.

Additional Key Terms

Allowed Amount: Maximum amount your insurance will pay for a covered service. Providers may bill more, but insurance only pays up to this amount.

Balance Billing: When a provider bills you for the difference between their charge and what insurance paid. Often illegal under the No Surprises Act.

Claims: Requests for payment that you or your healthcare provider submits to your insurance company.

Coordination of Benefits: The process that determines which insurance pays first when you have multiple plans.

Essential Health Benefits: Ten categories of services that all marketplace plans must cover, including emergency services, prescription drugs, and preventive care.

Exclusive Provider Organization (EPO): Plan that covers only in-network providers, except for emergencies. No referrals needed.

Health Maintenance Organization (HMO): Plan with lower costs but requires you to choose a primary care doctor and get referrals for specialists.

Health Savings Account (HSA): Tax-advantaged savings account for medical expenses, available only with high-deductible plans.

Lifetime Maximum: Total amount your insurance will pay over your lifetime. Most plans now have no lifetime limits for essential health benefits.

Medical Necessity: Healthcare services needed to diagnose or treat an illness that meet accepted medical standards.

Preferred Provider Organization (PPO): Plan offering more flexibility to see any provider, but costs less for in-network care.

Qualifying Life Event: Major life change that allows you to enroll in or change insurance outside open enrollment.

Special Enrollment Period: Time outside open enrollment when you can change insurance due to qualifying life events.