The “VA” is the Veterans Administration.
Here is how it works. If a veteran is eligible for medical care from the VA - and not all veterans are - they have to enroll. Based on where they live, they are assigned to a Community Based Outpatient Clinic. If they are lucky, there might be more than one Primary Care Physician in that clinic. If not - they get to see whoever happens to staff that clinic. Specialty care means going to a hospital that takes patients from a collection of nearby CBOCs. Keep in mind that for the veteran, they may go to see a specialist in a hospital that is not the nearest VA Hospital. If they need emergency care, or are just plain sick and need to see a doctor, then they are supposed to go to the nearest VA Hospital, which might be different from where they might go if their PCP or specialist wants them admitted.
Confusing - isn’t it! And in case you wonder - this is all a ‘take it or leave it’ proposition. I can’t tell you all how many veterans I’ve talked to at the diabetes clinic at the Durham VA Hospital who had to drive 3 hours or more to get to an appointment. As for choosing your doctor, or taking the best available treatment - it is like dealing with your local Post Office or DMV.