Box 12 on my W-2 has a D 16 then an amount. there is no D 16 section. What am i suppose to select?

[DianeW]

The letter "D" is what you need to select when entering your W2.  

Box 12 of the W2 is for many different items included on the  W2.  The "16" is an internal use for your employer, but is not an IRS description code.

D—Elective deferrals to a section 401(k) cash or deferred arrangement. Also includes deferrals under a SIMPLE retirement account that is part of a section 401(k) arrangement.