Re: Social Security and Birth Certificate Names
Your social security card would have your name listed as the applicant filed it. If the provider used one of your last names as a middle name, then that is what they recorded. The last time I filled one out there was a separate section for middle and last names.
Do you have a middle name?
from what I can find regarding Washington birth certificates, they do separate middle and last names on the application.
I would contact the Washington department of vital records to see if they retain a copy of the application for an original certificate of birth and see what it says on there.
I am not an attorney and any advice is not to be construed as legal advice. You might even want to ignore my advice. Actually, there are plenty of real attorneys that you might want to ignore as well.