This derived field indicates the basis on which the primary care group (PCG) code was assigned.

1 = GPPRAC was used to derive the code

2 = REGGMP was used to derive the code

3 = PURCODE was used to derive the code

4 = POSTCODE was used to derive the code

5 = POSTCODE allocated code, PCG code was blank

6 = POSTCODE allocated code, PCG code was 49998

9 = PCG code not known