You are unable to file a return (when utilizing the bona fide residence test on Federal Form 2555 Foreign Earned Income) until a full year has passed that you met the qualifications.
Per IRS Publication 54 Tax Guide for U.S. Citizens and Resident Aliens Abroad, starting on page 4:
Extension of time to meet residency tests. You cannot generally get an extension of more than 6 months. However, if you are outside the United States and meet certain requirements, you may be able to get a longer extension.
You can get an extension of more than 6 months to file your tax return if you need the time to meet either the bona fide residence test or the physical presence test to qualify for either the foreign earned income exclusion or the foreign housing exclusion or deduction. The tests, the exclusions, and the deduction are explained in chapter 4.
You should request an extension if all three of the following apply.
If you are granted an extension, it will generally be to 30 days beyond the date on which you can reasonably expect to qualify for an exclusion or deduction under either the bona fide residence test or the physical presence test.
How to get an extension. To obtain an extension, file Form 2350 either by giving it to a local IRS representative or other IRS employee or by mailing it to the:
Department of the Treasury
Internal Revenue Service
Austin, TX 73301-0045
You must file Form 2350 by the due date for filing your return. Generally, if both your tax home and your abode are outside the United States and Puerto Rico on the regular due date of your return and you file on a calendar year basis, the due date for filing your return is June 15.
What if tests are not met. . If you obtain an extension and unforeseen events make it impossible for you to meet either the bona fide residence test or the physical presence test, you should file your income tax return as soon as possible because you must pay interest on any tax due after the regular due date of the return (even though an extension was granted).
CAUTION! You should make any request for an extension early, so that if it is denied you still can file your return on time. Otherwise, if you file late and additional tax is due, you may be subject to a penalty.
Return filed before test is met. If you file a return before you meet the bona fide residence test or the physical presence test, you must include all income from both U.S. and foreign sources and pay the tax on that income. If you later meet either of the tests, you can claim the foreign earned income exclusion, the foreign housing exclusion, or the foreign housing deduction on Form 1040-X.
Note. The TaxAct program does not support IRS Form 2350 Application for Extension of Time To File U.S. Income Tax Return.
Per IRS Instructions for Form 2350:
Purpose of Form
Use Form 2350 to ask for an extension of time to file your tax return only if you expect to file Form 2555 and you need the time to meet either the bona fide residence test or the physical presence test to qualify for the foreign earned income exclusion and/or the foreign housing exclusion or deduction.
All other taxpayers should file Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return, to request an extension of time to file their returns.
Note: Do not file Form 2350 more than once for each move overseas. If, after meeting the qualifications for the “bona fide residence test” or the “physical presence test,” you remain abroad continuously for the following tax year(s) and require an extension, file Form 4868.
CAUTION! Form 2350 doesn’t extend the time to pay taxes. If you don’t pay the amount due by the due date (May 17, 2021, for a calendar year return), you will owe interest and may be charged penalties. For details, see Filing Your Tax Return, later.
CAUTION! If we give you more time to file and later find that the statements on this form are false or misleading, the extension is null and void. You will owe the late filing penalty explained later.
Period of Extension
If you are given an extension, it will generally be to a date 30 days after the date on which you expect to meet either the bona fide residence test or the physical presence test. But if you must allocate moving expenses (see Pub. 54), you may be given an extension up to 90 days after the end of the year following the year you moved to the foreign country.
Note. This form is filed separately from your tax return and mailed to the address listed previously.
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.