Certified Medical Assistant (CMA AAMA)Administrative: Billing, Coding and SchedulingMedium

A medical assistant is reconciling payments for the day. A patient's Explanation of Benefits (EOB) shows a 'coinsurance' amount of $20.00. The patient's plan has an 80/20 coinsurance. The allowed amount for the service was $100.00, and the deductible has already been met. How much did the insurance company pay?

  1. A$80.00
  2. B$100.00
  3. C$0.00
  4. D$20.00
Show answer & explanation

Correct answer: A. $80.00

With an 80/20 coinsurance, the insurance company pays 80% of the allowed amount after the deductible is met. In this case, 80% of $100.00 is $80.00. The remaining 20% ($20.00) is the patient's responsibility.

Why the other options are wrong

  • B. This is the total allowed amount, not what the insurance paid, as the patient has coinsurance.
  • C. The insurance company paid a portion of the allowed amount, so $0.00 is incorrect.
  • D. This is the patient's coinsurance responsibility, not the insurance payment.

Coinsurance Calculation

The patient's share of the cost of a covered health care service, calculated as a percentage of the allowed amount after the deductible has been met.

  • Calculated after the deductible is paid.
  • Expressed as a percentage (e.g., 80/20).
  • Patient pays their percentage, insurance pays the rest.
  • Based on the 'allowed amount,' not the billed amount.

Memory trick: Coinsurance: 'C' for 'Cut' of the bill, 'I' for 'Insurance's share'.

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