and Congress may be changing the Federal tax law.

earliest you can file 2017

floresbea75:
The dates that 2017 filing will open have not been announced yet, but should be announced soon.     Last year the IRS started taking returns on January 23, except for a few returns that they pulled early for testing.    TurboTax will start allowing efiling before then, but the return will just sit on a server at TurboTax until the IRS starts taking returns.   But once you submit it to TurboTax, if you discover an error, an additional W-2, etc., you won't be able to retrieve it to change it.  In that case, if the return is accepted by the IRS, you would have to file an amended return later.

You want to be sure you have received all your W-2's, 1099's (if any), etc. before filing.  Employers are supposed to furnish you a W-2 by January 31.

UPDATE:
The IRS recently announced a few days ago that it will start accepting returns for processing on January 29.

<a rel="nofollow" target="_blank" href="https://www.irs.gov/newsroom/2018-tax-filing-season-begins-jan-29-tax-returns-due-april-17-help-avai...>

When can I file for 2017?

Downloads for 2017 federal desktop software are currently available; online TurboTax became available on November 30.  State software typically takes longer to be available, so do not expect to be able to prepare a state return until later in January (at least).

Some federal forms are not finalized yet pending tax law changes that are still being worked on. Until the IRS finalizes forms for 2017, TurboTax has to wait to finalize forms in the software.  Many state forms are likewise not finalized.

Do not try to prepare your return using your pay stub.  The information on your pay stub will not match the W-2 that will be sent by your employers to the IRS.  Trying to file early and then ending up having to amend because you used incorrect/incomplete information is counter-productive.  If your return is incorrect, and you have to amend it, it will take months for the IRS to process your amended return.

Employers, banks, Social Security, brokers, etc. have until the end of January/early February 2018 to provide you with the documents you will need to enter on your 2017 tax return.

The IRS will not be accepting returns until an as yet undetermined date in January.  They will not begin issuing refunds until at least mid-February.

https://www.irs.gov/newsroom/irs-statement-on-2018-filing-season-start-date

https://www.irs.gov/newsroom/get-ready-for-taxes-plan-ahead-for-2018-filing-season-to-avoid-refund-d...

https://ttlc.intuit.com/questions/1908857-forms-availability-table-for-turbotax-state-except-busines...

https://ttlc.intuit.com/questions/1908857-state-forms-availability-table-for-turbotax-individual-per...

https://ttlc.intuit.com/questions/2580838-when-will-i-be-able-to-import-my-1099

https://ttlc.intuit.com/questions/1934390-how-do-i-import-my-W-2

https://ttlc.intuit.com/questions/2588751-why-can-t-i-import-my-w-2 

Tax Preparation Checklist

https://turbotax.intuit.com/tax-tips/tax-planning-and-checklists/tax-preparation-checklist/L7LHiDqGJ