Turbo-premier K1 box 5. I entered K1 interest. Turbotax asks right below : "Interest from U.S. Obligations in box 5" What is this? it is not on form k1; what/where?

If any of the interest or dividend income were from U.S. obligations, it would be mentioned in a note on or attached to the K-1. 

Interest on U.S. obligations is taxable on your federal return, but some states exempt it from state tax. 

If there is no notation on the K-1 that the interest or dividend amounts were from U.S. obligations, enter zero when asked for the amount by TurboTax.

Did the math, subtracted foreign source qualified dividends from 6A total dividends and put this in, but it is clunky - you don't specify the difference of total or qualified, so I used total as you mentioned "identifying" US dividends-I assume total.  Please be specific!  Actually, the amount of foreign qualified dividends and income are input from K1 16 B,C, etc. into turbo-tax,  so why doesn't it automatically subtract this or define what is needed in a popup?
Since had No foreign "interest" so used same number identifying all as USA - none identified on 1099's

so the original question about 6.... does it pertain to 6a or 6b since one is total dividends and the other is qualified ..... they are very different

I was wrong............ the true answer is the US Obligations are forms of T-bills, notes, etc. and you have to identify the amount as a % from your fund or stock or treasury note, etc.  no dividends, etc.  your input is very misleading.  one way of determining the amount is by referring to
<a rel="nofollow" target="_blank" href="https://2deaa804a6dc693855a0eba658c6bc03668a61900f643427d64d.ssl.cf1.rackcdn.com/Documents/product/distribution-tax/jif-supplemental-tax-dividends-derived-from-us-government-obligations-1217.pdf">https://2deaa804a6dc693855a0eba658c6bc03668a61900f643427d64d.ssl.cf1.rackcdn.com/Documents/product/distribution-tax/jif-supplemental-tax-dividends-derived-from-us-government-obligations-1217.pdf</a>

your answer was correct on interest, but dividends?

i don't have a form 8516,but K1 worksheets & k1 forms should say:  US Obligation (treasury notes, etc.) Interrest , and US Obligation (treasury investment instruments, etc.) dividends

TurboTaxIrene, that screenshot is the Turbotax input form, not a Schedule K-1 (Form 1065).

Can you please verify/clarify the answers to the original questions:
"i have interest and put it in box 5 as usual.  what does the question for US Obligations mean and where is it used?

Same question for Box 6B as it also asks for amount US Obligations under entering the Qualifying dividends."

You're right, the actual K-1 does not have a separate area for noting any amounts from U.S. obligations.  It would be included as a note at the bottom of the K-1 or attached to it.  
In the absence of any note, leave the boxes blank that ask for "Interest from U.S. obligations."
As I mentioned in my original answer, interest from U.S. obligations is sometimes treated differently on the state level.  That's why the boxes are included in the entry.

agree, and you are doing your best.   I just hope all the boxes have explanations that are clear in case I don't remember next year.  it's still clunky on this detail from my perspective - I can't imaging others.

I will pass your comments along to our programmers.

Can you clarify what exactly an "obligation" is?

Thanks! I have exactly the same question on my 2021 taxes.

US Obligations are government issued notes, Treasury bills and US bonds.