Deductibles, Coinsurance, and Out-of-Pocket Maximums: How to Compare Health Plans by Total Cost

Choosing a health plan usually means staring at a grid of numbers: premium, deductible, copays, coinsurance, out-of-pocket maximum. Most people anchor on one of them, often the premium or the deductible, and pick from there. That is how households end up paying hundreds or thousands more than they needed to.

The better approach is to add everything up the way it would actually be paid, at a few different levels of medical use, and compare totals. This guide explains each term, then walks through a worked comparison of two hypothetical plans.

The short version

• Your total annual cost is premiums plus what you pay out of pocket for care.
• Deductible: what you pay for covered care before the plan starts sharing costs (some services may be covered before it).
• Coinsurance: your percentage share of costs after the deductible.
• Copay: a flat amount for specific services, often regardless of the deductible.
• Out-of-pocket maximum: the most you pay for covered in-network care in a plan year. Once you hit it, the plan pays 100% of covered in-network costs for the rest of the year. Premiums do not count toward it.
• Comparing plans at low, medium, and worst-case spending shows which plan wins where. In our example, the low-premium plan wins only if spending stays under about $3,750 a year, unless an employer HSA contribution changes the picture.

How the money moves in a plan year

A few details that matter:

• Allowed amounts. Cost sharing is based on the plan's negotiated price for a service, not the provider's list price. In-network care uses these negotiated rates.
• Copays may or may not count toward the deductible, but they generally count toward the out-of-pocket maximum. Each plan's summary of benefits says how.
• Preventive care such as many screenings and vaccines is covered without cost sharing on most plans when received in-network.
• Out-of-network care may not be covered at all, or may have a separate, higher deductible and out-of-pocket maximum. Balance billing can also apply in some situations, though federal law now protects patients in many emergency and certain other scenarios.
• Family plans often have both individual and family deductibles and maximums. How they interact (embedded vs. aggregate) matters for families.

The worked example

Two hypothetical plans, individual coverage, all care in-network. For simplicity, assume all medical spending applies to the deductible, with no separate copays.

Plan B looks cheaper by $1,800 a year in premium. Plan A looks safer with a lower deductible. Which one actually costs less depends on how much care you use.

Total cost at different spending levels

The lines cross at about $3,750 of medical costs. Below that, Plan B's lower premium wins. Above it, Plan A's lower deductible wins, and in a bad year Plan A caps out $1,200 lower.

How a health savings account can flip the answer

Plans with high enough deductibles and certain other features can be HSA-eligible. An HSA lets you contribute pre-tax money (within annual limits set by law) to pay for qualified medical expenses, and employers sometimes contribute too. Unused money rolls over year to year.

Suppose Plan B is HSA-eligible and the employer deposits $1,000 a year into the account. Treating that deposit as a reduction in Plan B's cost:

Now Plan B is cheaper up to about $18,000 of medical spending, and its worst case ($9,600) is only $200 higher than Plan A's. Add the tax savings on your own HSA contributions and the case for Plan B strengthens further. HSA rules, including contribution limits and eligibility requirements, are set by federal law and adjusted periodically; check current IRS guidance.

The lesson is not that one plan type is always better. It is that employer contributions and tax advantages belong in the comparison, and leaving them out can point you to the wrong plan.

How to estimate your own spending

• Look at last year. Insurer portals usually show claims history with allowed amounts.
• List what you know is coming: planned procedures, a pregnancy, ongoing therapy, regular specialist visits.
• Price your prescriptions under each plan's drug formulary. Drug coverage often decides a comparison by itself, because tiers and coinsurance on specialty drugs can be large.
• Check networks. A cheaper plan that excludes your doctors or nearby hospital is not cheaper in any useful sense.
• Plan for a bad year. Even healthy people have accidents. The worst-case total (premium plus out-of-pocket maximum) is what you would owe if something serious happened.

A simple comparison worksheet

For each plan, write down:

1. Annual premium (your share, after any employer contribution).
2. Deductible, coinsurance, and out-of-pocket maximum (individual and family).
3. Copays for the services you use most.
4. Drug costs for your prescriptions.
5. Employer HSA or HRA contributions, if any.
6. Whether your doctors and preferred hospital are in-network.

Then calculate total cost at three levels: minimal use, your expected use, and worst case. The plan that does acceptably across all three, at a worst case you could survive financially, is often the right one.

Common misunderstandings

"The lowest deductible is the safest plan." Safety is about the worst case: premium plus out-of-pocket maximum. A low deductible with a high premium can cost more even in a bad year.

"Premiums count toward my out-of-pocket maximum." They don't. The maximum applies to cost sharing for covered care only.

"Once I hit my deductible, everything is free." Usually you move into coinsurance next. Care becomes fully covered only after the out-of-pocket maximum.

"High-deductible plans are only for healthy people." Sometimes they win even for heavy users, depending on premiums, employer HSA contributions, and out-of-pocket limits, as the example shows.

The takeaway

Compare health plans by total annual cost at several levels of use, not by premium or deductible alone. Include employer HSA contributions, your prescriptions, and your doctors' network status. Then make sure the worst-case total is a number you could actually pay. For questions about specific plans, the plan's own documents, your employer's benefits team, or a licensed agent or navigator can help.