Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 33; Flight Crew Total 2518; Flight Crew Type 33
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
General None Reported / Taken
Environment - Non Weather Related; Human Factors
Passenger seated in XX5 wore [a] mask during boarding however was not wearing [a] mask after being seated. When approached by the Flight Attendant the passenger said she had a medical exemption and did not have to wear the mask.  Customer Service Supervisor was called and passenger said they would comply; but continued to lift the mask off her face stating she had difficulty breathing.  As a possible solution the Flight Attendant offered the passenger an airline paper supplied mask as an alternative however the passenger's behavior became further defiant and belligerent.  It is my understanding other passengers were also expressing concerns about [the] passenger not wearing [a] mask.  I made the decision to have her removed from our flight.  Customer service escorted both she and her companion off the aircraft.  Customer Service Supervisor did a stupendous job.  Extremely professional and helpful.
Air carrier Captain reported a passenger was removed from the flight due to non-compliance with face mask policy.