Johny,

WELCOME TO THE AWS WELDING FORUM!!

You did not specify, which mode of transfer?

I am going to GUESS and even ASSUME that you are using GMAW Spray Arc Transfer; high voltage and shielding gas with 80% Ar or higher (I prefer 90/10 Ar/CO2). 

Now, if my assumption is correct, then NO there is no test for vertical or overhead.  Spray arc GMAW is not able to be used out of position.  Horizontal will basically be supported by material that is not part of the molten weld pool. 

He Is In Control, Have a Great Day,  Brent

Hey Johnny.
To get an "AWS welding certification", you demonstrate the ability to follow an approved welding procedure specification.
Individuals certify to AWS to use a welding or brazing process, with some variations like transfer mode, position and thickness.
There are thousands of different combinations of welding processes and parameters that a person can "Certify" to.
AWS is only one of the certifying Codes. There are many others.
Basically, if you can weld, braze or fuse it, you can "Certify" to do it.

GMAW or "MIG" has different transfer modes (the way the filler metal transfers across the arc and into the weld puddle).
Short Cirtuiting GMAW certification is separate from, Spray, Pulse and Globular.
Other certification options are based on material, filler metal, position, thickness, joint type, etc.

Lots and lots of variables.

Welcome to the welding world!
Just remember that a Real Welder doesn't flinch when burned, but finishes the weld before putting the fire out!
Learn to read the puddle to make good welds, and always fix your own mistakes.

Tim