Amy has a group medical policy through her employer with a $500 deductible and a 90% coinsurance provision. She incurs $1,500 in covered health care services. How much will her group insurance carrier pay?

To determine how much the group insurance carrier will pay for Amy's covered health care services, we must first apply the deductible, followed by the coinsurance calculation.

1. Deductible: Amy has a $500 deductible. This means she must pay the first $500 of her medical expenses out of her own pocket before the insurance starts to contribute.

2. Total expenses: Amy incurred $1,500 in health care services. After applying the $500 deductible, the remaining amount eligible for coinsurance is: [ 1,500 - 500 = 1,000 ]

3. Coinsurance: The policy has a 90% coinsurance provision, which means the insurance will cover 90% of the remaining $1,000. Thus, we calculate how much the insurance will pay: [ 1,000 \times 0.90 = 900 ]

Therefore, the group insurance carrier will pay $900 for Amy's covered health care services after considering the deductible and applying the coinsurance. This is why the answer of $900 is correct.