Coinsurance is a shared payment method between you and your insurer for medical costs, usually a percentage, activated after the deductible is met. It varies by plan and service type, influencing your out-of-pocket expenses significantly. Understanding coinsurance helps in selecting the right health plan and managing medical expenses effectively.

What is Coinsurance?

Coinsurance is the percentage of healthcare costs you pay after meeting your deductible. Unlike a copay, which is a fixed amount, coinsurance is a proportion of the total service cost.

How Does Coinsurance Work?

Once you’ve paid your deductible, coinsurance kicks in. For example, if your plan has 20% coinsurance, you pay 20% of healthcare costs, while your insurer covers the remaining 80%.

Examples of Coinsurance in Action:

  • After meeting a $1,000 deductible, a $5,000 medical bill would see you paying $1,000 (20%) and your insurance covering $4,000 (80%).
  • For a prescription with a total cost of $200, under the same coinsurance rate, you would pay $40.

Factors Influencing Coinsurance Amounts:

  • Plan Type: High-deductible plans often have higher coinsurance rates.
  • Service Type: Some services might have different coinsurance rates within the same plan.
  • In-network vs. Out-of-network: Out-of-network services can lead to higher coinsurance payments.

The Impact of Coinsurance on Healthcare Costs:

Understanding your coinsurance obligations can help you anticipate out-of-pocket expenses for healthcare services, making it easier to budget for medical costs.


Coinsurance is a vital part of health insurance that affects your out-of-pocket expenses. By understanding how it works, you can make informed decisions about your healthcare and choose the insurance plan that best fits your needs.