The numbering system for the DoD recurring BAAs are as follows:
SBIR Solicitation: the Fiscal Year (FY) followed by the last two digits of that year (e.g., FY23), and then the number .1, .2, or .3 to indicate the order in which the three different cycles are released for that fiscal year.
STTR Solicitation: the Fiscal Year (FY) followed by the last two digits of that year (e.g., FY23), and then the letter .A, .B, or .C to indicate the order in which the three different cycles are released for that fiscal year.
Each FY for the Federal Government begins each 01 October towards the end of the calendar year, so ‘FY23’ began 01 October, 2022.