Gateways are only required to be SIGIS certified if they wish to
use the SIGIS standards for IIAS transaction processing to
support FSA / HRA cards for SIGIS certified merchants. Gateways that
are not SIGIS certified, that process FSA / HRA card transactions through their gateway will see high card declines as the issuer / plan
administrator will not have the required information to approve the
transaction per IRS regulations for support an IIAS system.