The four words, in the order you pay them
Premium. What you pay every month to have the plan at all. It buys you nothing directly; it buys you the right to the rest of this list.
Deductible. What you pay out of your own pocket for covered care before the plan starts paying its share. A $3,000 deductible means the first $3,000 of covered bills in the year are yours.
Copay. A flat fee for a specific service, such as $30 for a doctor visit or $15 for a prescription. Some copays apply before the deductible is met, some after, and the plan document says which.
Coinsurance. Your percentage of a bill after the deductible is met. Twenty percent coinsurance means you pay $200 of a $1,000 bill and the plan pays $800.
Out-of-pocket maximum. The most you pay for covered, in-network care in a plan year. HealthCare.gov's definition: after you spend this amount on deductibles, copayments and coinsurance, the plan pays 100% of covered benefits. For 2026 the federal ceiling is $10,600 for an individual and $21,200 for a family, and plans can set theirs lower.
Read that last one twice. The premium is not in it.
A year, run through all four
Take a plan with a $3,000 deductible, 20% coinsurance, a $30 office copay, and a $7,000 out-of-pocket maximum. Premium $450 a month.
January: routine checkup, $30 copay. Preventive care is often covered before the deductible, and the copay is what you pay. Running total $30.
March: an MRI billed at $2,000 in-network. You have met none of the deductible, so all $2,000 is yours. Total $2,030. Deductible remaining: $1,000.
June: a minor procedure, $4,000. The first $1,000 finishes the deductible. The remaining $3,000 is split by coinsurance: you pay 20%, which is $600. Total $3,630. Deductible met.
September: an unplanned hospital stay, $25,000. Deductible already met, so coinsurance applies from the first dollar: 20% is $5,000. But the out-of-pocket max is $7,000 and you have already paid $3,630, so you owe only $3,370 more. The plan covers the rest. Total $7,000, and the cap is hit.
November: another $6,000 of follow-up. You pay nothing. The plan pays all of it.
Year end: $7,000 in medical bills, plus $5,400 in premiums. Total cost of that year: $12,400. The health insurance cost calculator does exactly this arithmetic for a plan you enter, with the premium included, because a comparison that leaves the premium out is not a comparison.
The premium is the number that lies
Two plans. Plan A: $250 a month, $6,000 deductible, $8,000 out-of-pocket max. Plan B: $500 a month, $1,500 deductible, $4,000 max.
In a healthy year with almost no claims, Plan A wins by $3,000, because you paid $3,000 in premiums and used none of the deductible, while Plan B cost $6,000 in premiums for the same nothing.
In a bad year that hits both caps, Plan A costs $3,000 plus $8,000, which is $11,000. Plan B costs $6,000 plus $4,000, which is $10,000. Plan B wins, by less than most people expect.
The honest way to choose is to add premiums to the worst-case cap and look at both numbers, then decide how much you would rather pay in a predictable monthly amount versus a lump you may never face. There is no universally right answer. There is a right answer for how much of a surprise bill you could absorb, which is a question about savings, not insurance, and one the net worth calculator is a reasonable place to start on.
What the out-of-pocket max does not protect you from
This is the section worth printing. HealthCare.gov lists what falls outside the cap, and every item on the list has produced a bill someone thought was impossible.
Premiums. They never count, however much you pay.
Anything the plan does not cover. If a service is excluded, there is no cap on it, because the cap only applies to covered benefits.
Out-of-network care. Many plans run a separate, higher out-of-network maximum, and some have no cap at all outside the network. The anaesthesiologist at an in-network hospital being out-of-network is the classic version of this.
Balance billing, meaning amounts a provider charges above what the plan considers the allowed amount. Federal protections now cover many emergency and surprise-bill situations, and they do not cover everything.
The upshot: the number on the plan is a ceiling for in-network, covered, allowed-amount care. Each of those three words is a place the ceiling can stop applying.
Deductibles that reset, and families that share one
Everything above resets on the first day of the plan year, which for most employer plans is 1 January and for some is not. A procedure in December and its follow-up in January can land in two different deductible years, which is a genuine reason people time non-urgent care.
Family plans usually carry both an individual deductible and a family one. Once any single person meets the individual figure, the plan starts paying for them. Once the family as a whole meets the family figure, it pays for everyone, regardless of who spent what. The same two-tier structure applies to the out-of-pocket max, and the federal rule is that no single person on a family plan can be made to pay more than the individual limit.
Where this fits in the rest of the budget
Health cover is one of the few lines where the right amount to budget is not the expected cost but the worst case you have decided to accept. A budget that only carries the premium is carrying half the line.
The other half is whatever the cap is on the plan you chose, sitting somewhere you could reach it. If that money does not exist, the cap is a number on a document rather than protection, and a lower-premium plan with a higher cap is a bet you cannot cover.
Life cover is a different question with a similar shape, which is why the life insurance calculator sits next to this one: both are about the size of a shock, not its likelihood.
The one-paragraph version
You pay the premium monthly no matter what. You pay covered bills yourself until the deductible is met. After that you pay coinsurance, a percentage, plus any copays. When your deductible, coinsurance and copays together reach the out-of-pocket max, covered in-network care is free for the rest of the year. Premiums, uncovered services, out-of-network care and balance bills sit outside that cap entirely. Compare plans on premiums plus worst-case cap, not on either alone.
Questions people ask
No, to both. Premiums buy the plan and count toward nothing inside it. HealthCare.gov lists monthly premiums explicitly among the costs excluded from the out-of-pocket limit. A year's total cost is premiums plus whatever you paid under the plan.
A copay is a flat amount for a specific service, like $30 per visit. Coinsurance is a percentage of the bill, like 20%, and normally applies only after the deductible is met. Both count toward the out-of-pocket maximum for in-network covered care.
The federal ceiling on Marketplace-compliant plans is $10,600 for an individual and $21,200 for a family. Individual plans can and often do set a lower cap. Once you reach it through deductibles, copays and coinsurance for in-network covered care, the plan pays 100% for the rest of the year.
In a low-claims year, usually. In a high-claims year, often not by much, because the higher deductible comes with a higher out-of-pocket max. Add annual premiums to the worst-case cap for each plan and compare those two totals, then ask how much surprise bill you could actually cover from savings.
