I live in the UK and according to publication 915 page 5 my social security benefits should not be taxable but TurboTax shows a taxable amount, how can I get around this?

[MarilynG]

Did you indicate in the MY INFO section that you are a resident of 'Foreign Country' under 'State you lived in'? (screenshot).

Here's a quote from taxesforexpats.com regarding Social Security Income:

"Social Security payments originate from the US and can therefore not be claimed as part of a FEIE (Foreign Earned Income Exclusion). 85% of your benefits are subject to taxation when you file your US expat taxes, and you may liable for incurred taxes in the foreign country in which you reside, as well. If you have questions about the taxes for which you’re liable in the country you call home contact that country’s designated embassy in Washington DC."

If you are being taxed on this income in the UK, don't include it in your US Return. 

https://www.taxesforexpats.com/articles/expat-tax-rules/social-security-expat-taxes.html