Not sure if it really matters. But I make sure even if different offices.
That my A1C is done at the same lab. Because I've learned that
different labs have different numbers they use. So I wouldnt
take to much stock to different numbers.

I would use the one that does your numbers the most. Like mine
is almost always done at my primary, or the hospital with them.
So that is were I have mine done.

Donna