CMV IgG was 12 what does it mean?

An IgG level of 12 for cytomegalovirus (CMV) indicates that you have been previously exposed to the CMV virus and have developed antibodies against it. IgG antibodies are produced by the immune system in response to an infection, and they provide long-term immunity against the virus. A CMV IgG level of 12 is considered to be a normal or negative result, indicating that you are not currently infected with CMV.