There have been a lot of questions pertaining to the eligibility of 2 services of E542.  The ministry responded to the following questions: 
  
Question  - what is the intention of this code, which is commonly known as a “tray fee”? 
Answer – The E542 “when preformed outside hospital” codes were negotiated to assist with the cost of providing services outside of a hospital. Hospitals receive a global budget for property, equipment, supplies and personnel, whereas clinics do not. 
  
Question – In which situation(s) would E542 qualify for more than one service and what are the determining factors of the second service? 
Answer – The E542 is not eligible for codes which are not identified as eligible in the Schedule. 
  
Question – Example, if 2 joint injections were performed – G370 + G371, would 2 services of E542 be payable?  
Answer – the Schedule only states G370 is eligible with the E542 add on. 
  
Question – Example, if G370 and G328 were performed, would 2 services of E542 be payable? 
Question – Example, if Z156 and Z162 were performed, would 2 services of E542 be payable? 
Answer – For your other examples, if the two services are both eligible for the E542, then E542 can be billed at 2 services. 
  
Example – if G370 + G371 is claimed, only E542 x1 is allowed (1 qualifying service). 

Example – if G370 + G328 is claimed,  E542 x2 is allowed (2 qualifying services). 

Example – if Z116 x2 is claimed, only E542 x1 is allowed (1 qualifying service). 

Example – if Z156 x1 and Z162 x1 is claimed, E542 x2 is allowed (2 qualifying services). 
  
In summary, two services of E542 is not eligible when only one qualifying service is provided.  Two services of E542 is only eligible if two qualifying services are provided.