Grandfathering is a term that means the old rules will apply for a specific period of time. After the grandfathering period is over, the new rules kick in and the amount you pay for the drug will likely increase. Some drugs are grandfathered indefinitely.

The grandfathering rule applies only to those people that have been taking a non-preferred drug before their new drug plan is launched. If you are prescribed a non-preferred drug after your drug plan launches, you will pay the highest amount (co-pay) for your prescription.

Here’s how grandfathering works in the Reformulary:

If you are taking a non-preferred drug before your Reformulary plan starts, the amount you pay for that drug (your co-pay) will increase when your new drug plan launches.

If the non-preferred drug you’re taking is grandfathered, you will have some extra time before the amount you pay (co-pay) goes up.

Continue paying the lowest co-pay in your plan when: You talk to your doctor or pharmacist and switch to a preferred drug on the Reformulary. The preferred drug is considered just as effective as the non-preferred drug you’re taking now.

Pay a higher co-pay when: You continue taking the non-preferred drug after the grandfathering period has ended.

Sometimes only specific DINs are grandfathered, meaning that not all strengths or forms of a specific drug are grandfathered.

Grandfathering may not apply to new plan members.