A plan with 10% coinsurance after the deductible means that once you’ve paid enough out of pocket to meet your annual deductible, you pay 10% of the insurer’s allowed amount for each covered service and your insurance pays the remaining 90%. That continues for the rest of the plan year until your spending reaches your out-of-pocket maximum, after which the plan covers 100% of covered in-network care.
The Deductible Has to Be Met First
Before any coinsurance applies, you pay the full negotiated cost of covered services yourself up to your deductible amount.1HealthCare.gov. Deductible – Glossary If your deductible is $2,000, you’re responsible for the first $2,000 of covered medical bills at your insurer’s negotiated rate, not the provider’s sticker price.
Once you cross that threshold, the deductible is met and the plan shifts into cost-sharing mode. That’s when the 10% coinsurance begins. The deductible resets at the start of each new plan year, so the cycle starts over annually.
What Your 10% Is Calculated On
After you’ve met the deductible, you pay 10% of the insurer’s allowed amount for each covered service, and the insurer covers the other 90%.2HealthCare.gov. Coinsurance – Glossary The allowed amount is the negotiated rate your insurer and an in-network provider have agreed to, not whatever the provider’s original charge happens to be.
Say a surgeon bills $2,500 for an operation but your insurer’s negotiated rate is $1,200. Your 10% applies to $1,200. You owe $120, not $250.2HealthCare.gov. Coinsurance – Glossary In-network providers accept these negotiated rates by contract, so you automatically pay your 10% against the lower figure.
One thing to confirm against your plan documents: many plans use copays rather than coinsurance for routine office visits and prescriptions, and apply the 10% coinsurance only to larger services like hospital stays, surgery, and imaging. Your Summary of Benefits and Coverage spells out which services carry coinsurance and which carry a flat copay.
Your Out-of-Pocket Maximum Caps the Total
Even at 10%, costs can mount if you need a lot of care. The out-of-pocket maximum is the most you’ll spend on covered in-network services in a plan year. Once your deductible, coinsurance, and copays combined reach that cap, your insurer pays 100% of covered costs for the rest of the year.3HealthCare.gov. Out-of-Pocket Maximum/Limit – Glossary
For 2026 Marketplace plans, the out-of-pocket maximum cannot exceed $10,600 for an individual or $21,200 for a family.3HealthCare.gov. Out-of-Pocket Maximum/Limit – Glossary Many plans set their own maximums lower. Premiums don’t count toward the cap, and out-of-network spending generally doesn’t count either unless your plan says it does.4Office of the Law Revision Counsel. 42 USC 18022 – Essential Health Benefits Requirements
With a 10% share, hitting the cap takes a lot of covered care after the deductible. But for a serious surgery, a long hospital stay, or ongoing treatment, that ceiling defines your worst-case financial exposure for the year.
Out-of-Network Care Changes the Math
The 10% rate almost always applies only to in-network providers. When you see an out-of-network doctor, hospital, or lab, your coinsurance rate typically rises sharply, often to 40% or more of the allowed amount.5HealthCare.gov. Out-of-Network Coinsurance – Glossary
Out-of-network providers also haven’t agreed to your insurer’s negotiated rates, so they can bill you for the difference between their full charge and the allowed amount. That’s called balance billing, and it comes on top of the higher coinsurance percentage.6HealthCare.gov. Balance Billing – Glossary
There’s a federal exception for care you didn’t choose. Under the No Surprises Act, most emergency services and certain out-of-network services delivered at in-network facilities are capped at your in-network cost-sharing level, and balance billing above that level is prohibited.7Centers for Medicare & Medicaid Services. No Surprises Act Overview of Key Consumer Protections For a 10% plan, that means your share of a covered emergency bill stays at 10% even if the ER is out of network. If you actively choose an out-of-network provider for non-emergency care, the higher out-of-network coinsurance and balance billing still apply.
Preventive Care Doesn’t Trigger the 10%
Federal law requires most health plans to cover certain preventive services at no cost — no deductible, no coinsurance, no copay. These include services rated “A” or “B” by the U.S. Preventive Services Task Force, immunizations recommended by the CDC’s Advisory Committee on Immunization Practices, and specific preventive screenings for women, children, and adolescents recommended by the Health Resources and Services Administration.8Office of the Law Revision Counsel. 42 USC 300gg-13 – Coverage of Preventive Health Services
Annual wellness exams, blood pressure and cholesterol screenings, mammograms, colonoscopies, and routine vaccinations commonly fall in this category. You won’t owe the 10% on these as long as you use an in-network provider and the service is coded as preventive rather than diagnostic.
Family Plans Work a Little Differently
On a family plan, how the deductible is structured decides when any one family member starts paying only 10%. There are two common structures:
- Embedded deductible: Each family member has an individual deductible inside the larger family deductible. Once one person meets their individual amount, their care moves to the coinsurance rate even if no one else has spent anything.
- Aggregate deductible: The family shares a single deductible. No one’s care is covered at the coinsurance rate until combined family spending meets the full family deductible.
Your Summary of Benefits and Coverage states which structure applies. The individual out-of-pocket maximum ($10,600 for 2026) also functions as a cap within a family plan, so no single member should spend more than that in a year even if the family cap is higher.3HealthCare.gov. Out-of-Pocket Maximum/Limit – Glossary