Just married on a K-1 visa, what's the best way to file?

You have choices. 

You can file Married Filing Separately or elect to file a joint return. 

No, a spouse is never considered your dependent on a U.S. tax return. 

If you choose to file Married Filing Jointly, which is usually the most advantageous way to file, especially in your situation where your spouse has no income, please follow these steps. 

1. Prepare the return in the software
2. Select “Spouse is a nonresident alien or dual-status alien spouse” and then select to make the election
3. Use the ITIN for the nonresident if applicable. If no ITIN, use 999-88-9999 and erase after printing*
4. Enter worldwide income for both spouses*
5. Select “Foreign Taxes” under “Deductions and Credits” “Estimates and Other Taxes Paid”
6. Continue through the interview for the credit or deduction*
7. Select “File by Mail” and print the return
8. Both sign statement provided by TurboTax software
9. IF ITIN used, mail tax return and statement to address indicated on TurboTax instruction sheet
10. IF NO ITIN, white-out the bogus SS#, include W-7 (application for ITIN) and mail package to the address indicated on W-7 instructions (Austin, TX)* SEE NOTE BELOW

NOTE: If your spouse already applied for a Social Security Number, and if the Social Security Number is expected before the due date of your return, wait until you receive the Social Security Number.

If you apply for ITIN and your spouse late receives a Social Security Number, use the Social Security Number for her going forward.

• For the first year you want to file an election to have the spouse treated as a resident for tax purposes, you must file MFJ
• The first year filing MFJ, inform the IRS of your election.
• Spouse is taxed as Resident for tax filing purposes
• Report all worldwide income, including all foreign income.
• May be allowed a Foreign Tax Credit or the Foreign Earned Income Exclusion (FEIE).

Election is valid until suspended or revoked

Once revoked, the election is no longer available to that non-resident alien

HERE is a TurboTax link with more information although the steps have been undated and reflected above.