What is the difference between a medical expense reimbursement plan (under Code section 105) and a Health Reimbursement Account?

An employer has a MERP in place and has been approached about establishing a HRA. I cannot seem to figure out what the difference is besides the rollover from year to year.

There is very little difference. A few weeks ago there was a discussion about this topic, try this link.

http://benefitslink.com/boards/index.php?showtopic=37066 it is under Cafeteria Plans

Good luck.