Your 1099-MISC may show an account or other unique number the payer assigned to distinguish your account. This is an informational only field and does not have to be entered anywhere into to TurboTax.
"TurboTaxDawnC TurboTax TaxPro"
2018 Instructions for Form 1099-MISC
https://www.irs.gov/pub/irs-pdf/i1099msc.pdf