Updated September 2026 · Reviewed by the CoverageCo team
A copay is a flat fee for a service, $30 for a doctor visit. Coinsurance is a percentage of the cost, you pay 20%, the plan pays 80%. Copays are predictable regardless of the bill; coinsurance scales with it, which matters enormously for expensive care.
Key takeaways
- Copay = fixed dollar amount. Coinsurance = percentage of the bill.
- Coinsurance usually applies after you've met your deductible; copays sometimes apply before.
- Both typically count toward your out-of-pocket maximum.
- For big-ticket care, coinsurance is where the real exposure lives.
The difference in one example
Say a procedure costs $4,000 and you've already met your deductible.
With a $50 copay, you pay $50. With 20% coinsurance, you pay $800. Same procedure, same plan structure, sixteen times the difference.
Now flip it to a $120 office visit. The $50 copay still costs $50. The 20% coinsurance costs $24. Coinsurance is cheaper on small bills and far more expensive on large ones.
| Service cost | With a $50 copay | With 20% coinsurance |
|---|---|---|
| $120 office visit | $50 | $24 |
| $1,000 imaging | $50 | $200 |
| $4,000 procedure | $50 | $800 |
| $40,000 surgery | $50 | $8,000 (until you hit your out-of-pocket max) |
How they interact with your deductible
Coinsurance generally kicks in after you've met your deductible. Before that, you're typically paying the full negotiated cost yourself.
Copays often work differently, many plans apply a copay to certain services like office visits or generic prescriptions even before the deductible is met. That's why you can have a high-deductible plan and still pay just $25 to see a doctor.
Whether a copay counts toward your deductible varies by plan. It usually counts toward your out-of-pocket maximum, but not always toward the deductible.
What this means when comparing plans
A plan advertising low copays looks appealing, and for routine care it genuinely is. But copays rarely apply to the expensive things, surgery, hospitalisation, specialist procedures. Those usually run on coinsurance.
So the practical read is: copays tell you what routine care feels like, coinsurance and the out-of-pocket maximum tell you what a bad year costs. Look at both, and weight the second one by how much financial disruption you could absorb.
Common questions
Does a copay count toward my deductible?
Often not. Copays frequently count toward your out-of-pocket maximum but not your deductible. It varies by plan, so check the summary of benefits.
Which is better, a copay or coinsurance?
Neither is universally better. Copays are predictable and usually cheaper on expensive care; coinsurance can be cheaper on low-cost services. What matters is your expected mix of routine and major care.
Do I pay coinsurance before my deductible?
Generally no. Coinsurance typically applies after you've met the deductible. Before then you usually pay the full negotiated rate for services subject to the deductible.
What is an out-of-pocket maximum?
The most you'll pay for covered in-network care in a plan year. Once you reach it, the plan pays 100% of covered services for the rest of the year.