How to input final distribution from a private limited partnership ( I was limited partner)? and should this qualify as long term capital gain?

As a partner in a partnership you should be maintaining a basis schedule (tax basis) of your investment in the partnership.

This begins with your initial capital contribution and is updated annually for the applicable lines on your K-1.

If you do not know your tax basis you will not be able to determine your final gain or loss.

The amounts reflected on your K-1 will be included on your tax return, but you will be missing the overall gain or loss on sale.  You know your final distribution amount which would be your sales price (final distribution), you could use 12/31/2017 as a sale date, your purchase date is when you acquired the partnership interest, but it appears you are missing the last piece which is your tax basis.

I will ask a follow-up question in a comment below.

On your K-1, what box is checked in section L?

The box checked in (L) is tax basis.  The initial contribution was used to purchase the building, and I remember the amount.  This didnt show up on any tax form, rather it shows my % in the partnership based on initial contribution (7.5%) Over the years there have been varying amounts in the "beginning capital account" entry, which reflected my share of the rent profit which wasn't distributed; but majority of profit was distributed quarterly basis.  thanks for your help.  for gain/loss on sale have no idea of either purchase or sales price, only  what I paid initially & distributed to me post sale.

ok.  A couple more pieces of information needed to make sure my response will provide the information you need.
1) The ending capital on your K-1.  Positive or negative?
2) The distributions reflected in this section, does this agree to actual distributions received?
3) Does the amount on line 19 code A agree to the distribution reflected in Section L distribution line?

1) positive  2) no less than amt received  3) yes

wondering if correct thing to do in working with the turbotax premier program is to only indicate that I sold my shares in this LLC?  The partnership was dissolved with underlying real estate sold.  ie partnership per se was not sold...also is my tax basis only the original amount invested, or should I add into cost basis the amount which was indicated in my beginning capital account at time of sale?

correction:  2) distributions DO match amount I received

I apologize the ending capital account is 0. The sale resulted in a large profit.   lets say the beginning capital account was $10,000, and the current year increase (reflecting sale) was  $50,000 with withdrawals and distributions the total, or  $60,000. The ending capital account 0.  Are you saying my basis is only the 10,000 from the beginning capital account, and that I can't deduct the initial sum which I contributed toward the initial purchase?

ok.  So based on your updated facts, this is what needs to happen:

1. Since you did not main a separate tax basis worksheet, we will assume that the K-1, which does indicate tax basis per your facts, is correct.
2. Since you indicate that there is basis remaining in Section L ending capital account, this means you have a capital loss on this investment.
3. You can handle the input of the required information in one of two ways:
1. You can indicate that you received zero proceeds and reflect the ending capital account amount as your tax basis.
2. You can indicate the proceeds as what is reflected as distributions, and your tax basis would be what ever the basis amount is BEFORE these distributions.
3. Either method should arrive at the same capital loss figure.
4. For the remaining pieces of information you would know the purchase date of the investment and then you would enter the "sales" date as either the actual or just use 12/31/2017.

I apologize the ending capital account is 0. The sale resulted in a large profit.   lets say the beginning capital account was $10,000, and the current year increase (reflecting sale) was  $50,000 with withdrawals and distributions the total, or  $60,000. The ending capital account 0.  Are you saying my basis is only the 10,000 from the beginning capital account, and that I can't deduct the initial sum which I contributed toward the initial purchase?

broc2 a few seconds ago

Then based on those updated facts, you have no gain or loss.  
Seems odd, but that is what you are saying in your example.
So based on these updated facts, you would enter $60,000 for the sales price and $60,000 for your tax basis.

Your tax basis tracks your initial investment and is updated every year for the annual activity including distributions.
So based on your facts you didn't lose anything, because you invested $10,000, "earned" $50,000.
You were then paid the $60,000 netting you to zero.  No gain or loss.

He didn't add capital of $50k for that current year, he earned it via the sale of the property, so the gain is $50k as I understand it.  He has no more interest ($0) at end of year since the deal is done and closed (final K1 I presume?).  That doesn't mean he had no gain or loss, it just means he has no more tax basis going forward for future years I believe.

The taxpayer is good to go based on the responses above.  Please don't add confusion to future individuals that may use this to provide assistance for their situation.

This.

A propos the next comment, here it needs to be specified that the "no gain or loss" is relative to the basis (i.e., you had all of your basis returned to you, not less than your basis (which would constitute a loss) or more than your basis (which would constitute a gain). The $50,000 presumably is given in one of the K-1 boxes for the different types of gain, which is how most people are thinking of gains. The way you stated it here strongly implies that zeroing out of the basis means that the $50,000 were "earned" in some tax-free way (which is what the next commenter was picking up on and correcting).

@karinm1  You just posted 1 word.  Do you have a question?