Optum Bank mails 1099-SA forms out at the end of January. It should also be available online as well, once it has been created. The online version will be available if you log in to your account at the bank's website:
Log in to the Optum Bank website: Optum Bank
Log in to the Optum Bank website: https://secure.optumhealthfinancial.com/CAP/Portlets/login.jsf?OFSP_login=consumer
Click on "register now" if you have not already set-up Optum Bank online access
Once you are logged in, scroll down a bit until you see "Statements and Documents" on the right side of the screen.
Click the button that says “View Your Statements and Documents.”
Click on the tax document you want for the desired year.