Since you need to meet the deductible before benefits begin (except for in-network preventive care, covered at 100%), your provider should file your medical claim before you make any payments to them. In some cases medical providers require payment prior to filing a claim. If so, you should use your PNC Bank debit card, if funds are available. If your in-network medical provider asks for full payment, point out to them that you are in a consumer-directed health plan and should not be required to pay the full cost of service up front. Then, when you receive your explanation of benefits (EOB) from AmeriBen, you will know the exact amount owed and can pay your provider using funds in your HSA with the PNC Bank debit card or out-of-pocket.
If you are filling a prescription, you can simply use your PNC Bank debit card to make the payment, up to the current balance in your HSA account. When you present your CVS/caremark ID card, the pharmacist should be able to calculate the amount you owe for your prescription, if your deductible has not been met. Remember to check your HSA balance before using your credit card. You will be charged a fee if you have insufficient funds and/or use the debit feature.