General medical services is the name used to describe the medical services provided by General Practitioners (GPs or family doctors) who, in effect, run private businesses independently contracting with the government.
The contract under which they work is known as the General Medical Services Contract.
Every practice gets a share of a total amount of money allocated towards primary care in GMS practices (the “Global Sum”).
This share is determined by the practice’s list size, adjusted for age and sex of the patients (children, women and the elderly have higher weights than young men because they cause a greater workload).
Furthermore, the practice gets an adjustment for rurality (greater rurality causes greater expenses), for the cost of employing staff (the “Market Forces Factor” (MFF), which captures differences in pay rates between areas.