My mom has a Medicare Eligible Health Reimbursement account through AT&T (she is retired). Is that considered the same as an HSA or MSA? Basically AT&T deposits $2,700 per year into the account for he

No, Health Reimbursement Accounts (HRA) are not the same as Health Savings Accounts (HSA).  Even though they are both used to pay or reimburse qualified medical expenses.

You do not need to report any information with regard to her HRA on the tax return.