What's the amount known as the "allowable amount", the "U&C amount" or the "R&C amount"?

The terms “allowable amount,” “U&C amount” or “R&C amount” vary by plan but refer to the same thing. The allowable, usual and customary or reasonable and customary amount is the amount usually charged for a given service by most providers in your area. This amount is determined by your dental care plan. If your dentist charges you more than this amount, you will not only be responsible for your deductible and coinsurance, but also for the entire difference between the U&C amount and the amount your provider charged. This concept only applies for out-of-network care, because PPO dentists have agreed to accept negotiated fees, which are by definition allowable amounts.