The 'core services' survey by Norfolk and Waveney LMC, launched late last month, asks 127 local practices what funded and unfunded services they provide.
LMC leaders plan to compare the results to a similar survey the LMC conducted ten years ago to reveal the amount of underfunded work practices have been forced to take on.
The LMC's chairman, Dr Tim Morton, said he plans to use the results in negotiations with his local area team over PMS reviews.
In July, NHS England ordered its 27 area teams to compile data for a PMS contract review, which GP leaders fear could strip millions of pounds from the profession.
Dr Morton said: ‘We are trying to get a baseline of what practices are doing. We are concerned that PMS reviews are not being based on accurate information.
‘Area teams are being told to look at PMS contracts. A lot of practices are feeling very vulnerable.
‘As an LMC we are trying to get an idea across our patch of where practices are in order to help discussions with area teams and CCGs. We are constantly talking with the five CCGs in our area about their plans for enhanced services.'
He added that the ongoing transfer of secondary care work into general practice is increasing workload for practices.
The survey includes questions about enhanced services and QOF scores.
The GPC is adamant that PMS funding should be redistributed within general practice. But the decision on how much money could be removed from general practice hinges on NHS England’s assessment of PMS practices’ baseline funding.
Payments for core services are likely to be redistributed among practices, but anything deemed effectively equivalent to an enhanced services payment could be withdrawn.