Do we have to retain EOBs for a certain period of time?

Many practices retain EOBs for up to seven years - a nuisance, but they come in handy if a payer does a retrospective audit and demands thousands of dollars in refunds (believe me, it happens). The IRS also might like to have a look. Take a look at what your contracts do or do not specify on this point. 

That said, there is no reason to keep the paper. A well-scanned version is just as legitimate - and easier to find later on. Just scan and store them by numerical assignment or whatever filing method works for your biller. 
