S corporation election timing definition

Yes. A corporation must elect S status in a timely manner.

This election is made on Form 2553, Election by Small Business Corporations to Tax Corporate Income Directly to Shareholders. It must be filed with the IRS no later than the fifteenth day of the third month of the corporation's tax year.

For example, if the tax year ends on December 31, the S Corp election must be signed and filed by the 15th day of March. If an S election is filed after the deadline, the election is missed for that tax year and it becomes effective the following tax year.