Interest free loans

Is it possible to get a large interest free loan, over $12k, from a family member without the IRS thinking it's a gift? Does the loan contract need to be legally registered some how? What taxes may the parties be liable for?

States NM to GA

Have a written loan agreement & a repayment schedule. The interest you would have had to pay is considered a gift, but it's probably below the $11,000 annual limit.