It seems this question is easier to lay out as a 'word problem' so here goes:

The Smiths have been happily married 30 yrs and are in their 50s

In 2016, Mrs. Smith inherited a home in Georgia, and moved there from TN, taking up residence and changing her car tags, license, and voter registration.

Mr. Smith continues to live and work in TN. His employer pays the expenses for his domicile in TN (rent, utilities, cable) as an incentive for Mr Smith to stay. He has a TN license and is registered to vote in TN.

Mr. Smith visits his wife's home in GA about a week out of each month, sometimes "working from home". The Smiths have always filed a joint tax return.

Mrs. Smith no longer works outside of the home, but makes a very meager living selling things online, for which she pays Schedule C taxes. (She has yet to make enough to be required to file under GA law).

For 2016, the Smiths filed as residents of TN, where there is no state tax.
They want to make sure they file properly re state taxes, and not get 'dinged' later.
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Question:
Should the Smiths for tax year 2017 file as full-time residents of GA?
or
Should they file with their residency situation separate, with Mrs Smith being full time and Mr. Smith part time based on the time he works in GA?

Thanks.

The Smiths have been happily married 30 yrs and are in their 50sIn 2016, Mrs. Smith inherited a home in Georgia, and moved there from TN, taking up residence and changing her car tags, license, and voter registration.Mr. Smith continues to live and work in TN. His employer pays the expenses for his domicile in TN (rent, utilities, cable) as an incentive for Mr Smith to stay. He has a TN license and is registered to vote in TN.Mr. Smith visits his wife's home in GA about a week out of each month, sometimes "working from home". The Smiths have always filed a joint tax return. Mrs. Smith no longer works outside of the home, but makes a very meager living selling things online, for which she pays Schedule C taxes. (She has yet to make enough to be required to file under GA law).
For 2016, the Smiths filed as residents of TN, where there is no state tax.They want to make sure they file properly re state taxes, and not get 'dinged' later.
---
Question:
Should the Smiths for tax year 2017 file as full-time residents of GA?=========>>>>>>>YES IT IS UP TO you;ONCE you and your spouse both agree to file jointly; if you don't, you have to file separately. ALSO, ONCE you meet the IRS definition of a married couple. If you qualify, you can file a joint return when living apart, as long as you're not legally separated.
or
Should they file with their residency situation separate, with Mrs Smith being full time and Mr. Smith part time based on the time he works in GA?=====================>>>>>>>>..AS SAID PREVIOUSLY THEY FILe EITHER mfj OR mfs ON THEIR GA RETURNS;IF THEY FIle mfs THEN MR SMITH NEEDS TO FILE HIS return with GA on his GA source income and claims it on sch A OF 1040 SINCE NO STYATE TAX IN TN while mrs smith files her GA return as a full time resident of GA.mr Smith may file his GA return on his GA source income that he earns in GA and claims it on his SCh A of 1040 aslongas he itemizes his return on 1040.Or if they want both of them may jointly file GA return on her GA source and his TN/G source income to GA and claims his TN source income on his sch a OF 1040.