The pilots, due to begin on 30 April, will allow out-of-area patients to register at participating practices in Manchester, Nottingham and London.
Patients can either remain registered with their home practice and be seen as a day patient or join the practice as a registered patient.
Although practices will receive a payment of £12.93 per day patient, concerns have been raised about how prescribing and secondary care commissioning costs for registered patients will be covered.
DH guidance on the pilots said that in future, new patient registrations would be factored into PCT budgets. However, for the pilot year, 2012/13, there would be no adjustments to PCT funding.
City and Hackney LMC chairwoman Dr Deborah Colvin said the lack of funding was a huge concern and could force PCTs to cut services.
‘Poorer boroughs like Tower Hamlets and Hackney will have to pay the prescribing and secondary care costs for people from richer boroughs,’ she said.
City and East London LMC chairman Dr Kambiz Boomla said large numbers of people working in the City of London would move practices. ‘The pilots are in danger of putting serious funding pressure on PCTs and clinical commissioning groups (CCGs),’ he said.
Manchester LMC secretary Dr John Hughes agreed. ‘It will cause major issues in London. These deprived areas will be swamped by commuters but they won’t have the funding.’
A DH spokeswoman said: ‘PCTs (and emerging CCGs) should seek to monitor the secondary care costs associated with out-of-area registrations. PCTs will manage any impact through their planning and financial management.’
The poll was carried out by the mail order pharmacy Pharmacy2U.