Short answer: A deductible is what you pay before the plan starts paying; a copay is a flat fee for a specific service; coinsurance is your percentage share of a cost after the deductible; and the out-of-pocket maximum is the most you’ll pay in a year before the plan covers 100% of covered services.
These four terms describe how you and your health plan split the cost of care. Premiums (what you pay each month just to have coverage) are separate and don’t count toward any of them.
Deductible: the amount you pay for covered services before the plan begins to pay. If your deductible is $2,000, you generally pay the first $2,000 of covered care yourself (though many plans cover preventive care, and sometimes a few copay services, before the deductible).
Copay (copayment): a fixed dollar amount you pay for a specific service, say $30 for an office visit or $15 for a generic drug. Copays may apply before or after the deductible depending on plan design.
Coinsurance: your percentage share of a covered cost after you’ve met the deductible. With 20% coinsurance, the plan pays 80% and you pay 20% until you reach your out-of-pocket maximum.
Out-of-pocket maximum: the most you’ll pay for covered, in-network services in a plan year. It includes your deductible, copays, and coinsurance (but not premiums). Once you hit it, the plan pays 100% of covered services for the rest of the year. For 2026, the ACA caps this at $10,600 for self-only and $21,200 for family coverage on non-grandfathered plans.
Sources
- CMS, HealthCare.gov Glossary (deductible, copayment, coinsurance, out-of-pocket maximum): healthcare.gov glossary
- 2026 ACA out-of-pocket maximum ($10,600 / $21,200): HHS Notice of Benefit and Payment Parameters.
Content history
Originally published: June 16, 2026
Last reviewed: June 16, 2026