INSURANCE

What is coinsurance and how does it work?

SHORT ANSWER

Coinsurance is the percentage of a covered cost you pay after meeting your deductible — for example, 20% while the plan pays 80%. It keeps applying until you hit your out-of-pocket maximum, after which the plan covers the rest of covered services for the year.

Coinsurance is the cost-sharing that kicks in once your deductible is met. Instead of a flat copay, you pay a set percentage of the covered charge and the insurer pays the rest — a common split is 20% you, 80% the plan. It continues on each covered service until your total spending reaches your out-of-pocket maximum, at which point the plan pays 100% of covered services for the remainder of the plan year. Because it is a percentage, coinsurance on an expensive procedure can be substantial, which is why the out-of-pocket maximum matters as your backstop.

What to do, in order

  1. Find your coinsurance percentage in the plan’s summary of benefits.
  2. Remember it applies after the deductible is met, not before.
  3. Estimate your share on big procedures — a percentage can be a large number.
  4. Track spending toward the out-of-pocket maximum, where coinsurance stops.
  5. Check that in-network coinsurance rates are lower than out-of-network.

Common questions

How is coinsurance different from a copay?

A copay is a fixed dollar amount; coinsurance is a percentage of the cost. Coinsurance can be much larger on expensive care.

When do I stop paying coinsurance?

Once your out-of-pocket spending reaches your maximum for the year, the plan pays 100% of covered services and coinsurance stops.

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This is general information, not legal, tax, or financial advice, and it doesn’t create a professional relationship. Rules have exceptions and change over time. For advice on your specific situation, consult a licensed professional.