"repayment over $3000 per IRS Publication 17, chapter 12 page." wife received LTD and on approval of SSDI in 2018 retroactive in 2017, we had to repay a portion.

[Critter]

Repayment over $3,000.    If the amount you repaid was more than $3,000, you can recover the tax you originally paid using one of two methods. You can do it as a deduction on schedule A or a tax credit on line 73 of the 1040 form if when you included the income in a previous year, it appeared that you had an unrestricted right to it.

Figure your tax under both methods and compare the results. Use the method (deduction or credit) that results in less tax.

Method 1.    Claiming a deduction for the repaid amount. You deduct it as a miscellaneous itemized deduction on Schedule A  line 28.

This is the flow in TurboTax: 
Federal taxes > Deductions & credits > I'll choose what I work on > Other deductions and credits > Other deductible expense>Go thru to third screen> answer YES to "Did you have any other deductions that are not subject to the 2% limitation?"
Enter the amount you repaid under, "Claim of Right Repayment (Only if over $3,000).

Method 2.    Figure your tax claiming a credit for the repaid amount. Follow these steps.

1.      Figure your tax without deducting the repaid amount.

2.      Refigure your tax from the earlier year without including the income that you had to be repaid.

3.      Subtract the tax calculated in (2) from the tax shown on your return for the earlier year. This is the credit.

 This is the flow in TurboTax (This can only be done in the Forms mode of the Desktop version of TurboTax)

Go to FORMS (top right of main screen) > Form 1040 > Scroll below line 72 to "Other Payments and Credits Smart worksheet"
Please enter the credit on line D. 
This credit should show up on Form 1040 line 73
I've included a link to the IRS website for your reference: https://www.irs.gov/pub/irs-pdf/p525.pdf