Health insurance has maybe eight words of real vocabulary, and the industry acts like you were born knowing them. You were not. Here they are, in the order your money actually moves.
Premium, the subscription
What you pay every month just to have the plan, claims or no claims. It is the most visible number and the least predictive one. A low premium usually means the plan shifts more cost to you when you actually use it.
Deductible, your share before the plan kicks in
The amount you pay for covered care each year before insurance starts paying its share. A 2,000 dollar deductible means the first 2,000 of most services comes from your pocket. Important nuance: thanks to the ACA, preventive care, annual physicals, screenings, immunizations, is covered before the deductible on every Marketplace plan.
Copay, the flat fee
A fixed price for a specific service: 30 dollars to see your doctor, 15 for a generic prescription, 75 for urgent care. Copays are the easy part, the price is printed on the card.
Coinsurance, the percentage split
After you meet your deductible, you and the plan split the bill, commonly 20 percent you, 80 percent plan. On a 40,000 dollar surgery, that 20 percent is real money, which is exactly why the next term exists.
Out-of-pocket maximum, the ceiling
One Florida example, start to finish
Maria in Boynton Beach has a plan with a 2,000 deductible, 20 percent coinsurance, and a 6,000 out-of-pocket max. In March she has outpatient surgery billed at 30,000 (network rate: 18,000). She pays her remaining deductible (2,000), then 20 percent of the rest until her total spending hits 6,000, and stops there. Insurance covers everything else all year, including the physical therapy that follows. Her premium never changed; her ceiling saved her.
That is the whole vocabulary. Every plan comparison, Marketplace, Medicare, groupis just these five numbers arranged differently.