In addition to merging practices, GPs are also increasingly working together to deliver services at scale, the survey suggests.
Three out of five GP partners said their practice was part of a network or collaborative working system, such as a federation or super-practice - a result that supports findings from recent Nuffield Trust/RCGP research on collaborative working in primary care.
A total of 5% of GP partners said their practice had merged in the past 12 months, and 8% said their practice planned to do so in the coming year.
The survey found that 40% of GP practices were not part of any wider network or group. Federations were the form of collaborative working they were most likely to be involved in - 36% said they had joined a federation, while 14% were part of a GP network.
Just 5% were part of a super-practice with 25,000 patients or more, while others reported being part of clusters or organisations such as the multispecialty community providers and primary and acute care systems being rolled out under NHS England's Five Year Forward View plans.
GPs expressed concerns about moving to larger-scale services around continuity of care, and some felt the move could increase workload rather than reduce it.
One GP said: 'Small is beautiful. We have an excellent happy loyal team. I do not want to expand and take on other people's problems even for financial gain. It just isn't worth it.'
But others argued it was the only option. One respondent said: 'We work in a cluster to undertake projects which suit our patients and on things which we might gain from by bulk buying or economies of scale. We also also join with other clusters to bid for commissioned work.'
However, in some areas practices that had joined federations or joint working systems said the move had left them facing new problems. 'We have a federation, but the CCG won't entertain moving the money with the work. It is in deficit £25m so cannot see further than today. If the federation could be paid for the activity it is willing to do then massive savings would be made but the CCG will not take the risk of destabilising the local trust as it has contracted with them.'