Most companies using Startomatic are eligible. 

There are a number of limitations on S-corporations; for example, they must have no more than 100 shareholders, all of whom must be individuals (i.e., not corporations, LLCs, or other entities), and none of whom may be nonresident aliens.

For more details, or to check to be sure your company will be eligible to make an S-election, visit https://www.irs.gov/instructions/i2553 to review the IRS's Instructions for Form 2553.

The deadline for a newly-formed company to make an S-election can vary, but is typically 75 days after the company is formed. 

You can also make an S-election for a later fiscal year. 

If you need more details, review the "When To Make the Election" section of this IRS website: https://www.irs.gov/instructions/i2553.

"Pass-through" taxation means that the company itself pays no federal income tax. Instead, the owners of the company report the company's profits on their personal tax returns and pay the taxes directly.

S-corporations and LLCs (usually) enjoy pass through taxation.

This is in contrast to the typical taxation of a traditional corporation (a so-called "C-corporation"), which pays federal income taxes on its income, and then the shareholders also pay federal tax on distributions received from the corporation (often called "double taxation").