Does Medicare A or B pay for HAA trips?  

Part b pays 80% of the fee schedule Medicare publishes for ambulance services i.e rw base rate +
loaded mile.  

secondary carrier pays 20%

part A is for hospital services only applies if an ambulance is utilized for round trip for services not available then the hospital would bill Medicare under Part A and the ambulance air or ground would billl the hospital and the full rate of the trip