Depending on your jurisdiction, the AT modifier should be applied.
"For tetanus and rabies vaccines to be covered for payment, the patient must have undergone a recent injury or direct exposure. Providers have been instructed to report modifier "at" indicating acute treatment for these recent injury or direct exposyre situations. Effective dates of service October 11,2007 and after, this edit has been set up to allow payment for the tetanus and rabies vaccines only if the AT modifier is being reported"
"90696, 90703, 90714, 90715, 90718, 91675, 90676 and admistration codes 90471, 90472"
This was a buliten that crossed my desk for Part B Maryland and Pennsylvania locations.
hope this helps