What Does Coinsurance Mean in Health Insurance?

Coinsurance is the percentage of a covered medical bill that you pay after you've met your deductible. If your plan has 20% coinsurance and you get a $5,000 procedure, you pay $1,000 and the insurer pays $4,000. The most common split is 80/20, but it varies by plan and sometimes by the type of service.

When Coinsurance Applies

Coinsurance only kicks in after you've met your annual deductible. Before that, you're paying the full allowed amount for most services (except preventive care, which is free). After you hit the deductible, you and the insurer start splitting costs based on the coinsurance percentage.

The Metal Tier Breakdown

On the ACA Marketplace, metal tiers roughly tell you how costs are split over a full year. Bronze: the plan covers about 60%, you cover 40%. Silver: 70/30. Gold: 80/20. Platinum: 90/10. These are actuarial values, not exact coinsurance rates for each visit, but they give you a solid sense of how much financial risk you're taking on.

Out-of-Network Coinsurance

Plans often charge much higher coinsurance for out-of-network care. You might owe 20% in-network but 40% to 50% out-of-network. And in some plans, out-of-network costs don't count toward your out-of-pocket maximum, so there's no ceiling on what you could end up paying. Staying in-network matters.

When It Stops

Your coinsurance payments count toward your annual out-of-pocket maximum. For 2026, ACA plans cap that at $10,150 for individuals and $20,300 for families. Once you reach it, the plan pays 100% of covered in-network services for the rest of the year. If you're facing major medical costs, the out-of-pocket max is more important than the coinsurance rate.