Previously there were over a dozen different paths for active-duty sailors to become commissioned officers, "Seaman to Admiral" being just one of them. This wide array of programs lacked uniformity in benefits, selection procedures, educational opportunities, and program requirements. This created a very confusing web of program applications, deadlines, and choices for fleet applicants and was very cumbersome for the Navy to manage and administer.
For all of these reasons and more, the Navy combined most of these current commissioning paths into one consolidated program that preserves the "Seaman to Admiral" name made popular by Admiral Jeremy Boorda: Seaman to Admiral-21 (STA-21).
The STA-21 commissioning program is designed to meet the goals of the Navy in the 21st century, while at the same time creating a fair and equitable system for outstanding active-duty sailors to receive a college education and become commissioned officers in the unrestricted line (URL), special duty officer (intelligence), special duty officer (information warfare - formerly cryptologist), nurse corps (NC), supply corps (SC), civil engineer corps (CEC), explosive ordnance disposal (EOD), or SEALs. It is extremely competitive for sailors selected from the fleet; the average selection rate has ranged from 10% to 24% from 2001-2010.
In 2011, the program became much more selective for non-nuclear applicants. In 2013, they selected 19 non-nuclear officer candidates out of 542 applicants (3.506% selection rate). For nuclear applicants, the average selection rate has ranged from 20% to 25% since 2010.
All STA-21 Officer Candidates report to the Naval Science Institute before going to their assigned college.