Wow, lots going on with this scenario. I'm a little confused as to how OY2 from Oct 2021-30 April 2022 was just paid for? It concerns me that it sounds like the option might have been exercised, but the money wasn't available until recently, In addition, who is the "they" that is paying for OY3? Ultimately, because fiscal regulations are so complex. I'm going to refer you to the governing documents you should be conslting to address/answer any question relating to fiscal law and regulations. You'll want to review and become familiar with the pertinent information and sections in the DoD Financial Management Regulations which you can find at Financial Management Regulation (defense.gov). Based on your question, I'd probably start with Volume 10, Chapter 1, and/or possibly Volume 14. This should also be an area of expertise for your program's business/financial manager. As in all cases, also be sure to consult your program attorney for guidance as you proceed.