5G on More Everything Unlimited Plan?

Hello.  I share a More Everything Unlimited Talk, Text & 15GB plan with my mom and sister.  We have no desire to change the plan but I need a new phone.  All the phones currently on sale are 5G phones.  Will they work with this plan?  Will I get 5G access or will I be restricted to 4G LTE?  Is there a fee I can pay to keep the current plan but still get 5G access?