Section 199A - Qualified Business Income Deduction. Does anyone know how to get this worksheet in 2018 premier version? I am unable to find this.

What is the source of the income you have that is eligible for the Section 199A deduction?  My answer can depend on this.

I have an S-Corp that I believe would qualify but would like to work through it step by step guide. I do not see if as an option in TT at least my version. I can show form and see something mentioned about it but would like to have a guide to see if i qualify.

I have the same question, please clarify which TT version you are using in the explanation below.

When will turbo tax have QBI for partnerships updated in their software?

If you'd like to post a separate question to receive assistance on your question, we can provide an answer specific to your situation.  

the software does not have any screens to enter the QBI deduction for partnerships for the 2.5% of the original investment. I am using a Mac and over a week ago I talked to someone from turbo tax and they could not help me. they said they had not fixed the problem and keep trying back. I have checked everyday and nothing updated. Very poor execution and very disappointed.

It is calculated through the interview.  For starters, the QBI calculation is complex, especially if the individual is above the 157,500 thresholds if single, married filing separately, or head of household, or 315,000 if Married Filing Joint.  But these are the steps needed to help the program calculate QBI correctly:

1. Under Wages and Income, scroll down to the Subheading Business Income, and select K-1.  
2. On the screen Choose Type of Activity select whether it is Business Income  or Rental Real Estate, (if business income, answer questions regarding your stock ownership and Material Participation, if rental real estate, answer the appropriate questions about being a Real Estate Professional, Active Participation, and Special Handling.)
3. On the screen Check Boxes That Have an Amount, you should select Box 17 info.
4. You should see codes V and W on the K-1 (if you do not, this is would be one reason why the QBI does not calculate.  This information must be entered from the information on the K-1 for QBI to calculate).
5. Select any that apply on the screen Other Situations, and any information to the question Did this business receive qulified payments from a cooperative.
6. Answer the question about anticipated income on the next screen, We're almost done.  If anticipated income is below the threshold, QBI will calculate after that screen.  If above, you will provide additional information, and QBI will calculate according to the final results of the calculations.

You may find the following FAQ helpful:  https://ttlc.intuit.com/replies/7036528

I do not see the Scroll down and select Wrap up tax breaks. I believe I need to purchase home and business TT as I have premier that lets you do schedule k. I have my business taxes done by another so maybe i need to upgrade?

Scroll down is a command for you to scroll down on your screen.  But if you are using desktop, you can go to Forms Mode to see the QBI Deduction Worksheet.  Your running refund/balance due at the top left also changes when the deduction calculates.  But you don't have to upgrade.  I was able to duplicate this using TurboTax desktop Deluxe, which is a step below Premier.  You are in the right program.  Check the Forms Mode.

how do you get to forms mode in Self-employed Live?

The online versions do not have the Forms Mode.  That is only a Desktop program feature.

In Turbo Tax Deluxe 2018, Intuit says "trust me" to compute the Qualified Business Income deduction, so in case of questions, there is no way to tell how TTD computed the figure.  Taxable income before QBI deduction was less than $157k.    Taxable income minus capital gains/dividends was more than QBI.   The QBI deduction calculated by TTD was less than 20% of qualified business income for sole proprietor.  How can that possibly be correct?  Shouldn't QBI deduction simply be 20% of the QBI?

Oops, IRS regulations have cut down QBI as generally defined in 199A by interpreting QBI as excluding adjustments to income attributed to the business, such as self-employed health insurance deductions, so Turbo Tax does this behind the scenes and is thus in accordance with the regulation.  Requires digging because TTD doesn't explain on the surface.

One thing I found was my QBI credit was not as much as I thought it would be.  Because I had a business loss the prior year and it carried it over and took it into account.

Have you seen this one?  There is a max on income.  

What is the 20% QBI Deduction and how it's calculated

https://ttlc.intuit.com/community/credits-and-deductions/help/what-is-the-qualified-business-income-qbi-deduction/00/27455