the answer… from OSP…
The NIH limitation is by council round, rather than submission date. Council rounds can be found on the NIH standard due dates page: https://grants.nih.gov/grants-process/submit/submission-policies/standard-due-dates
Here is the policy info on the limitation:
https://grants.nih.gov/grants/guide/notice-files/NOT-OD-25-132.html

Some additional guidance (including a table to show which deadlines fit into which year) can be found on the OSP website: https://research-support.yale.edu/sponsored-projects/office-of-sponsored-projects/proposals
Calendar Year 2026
| Advisory Council Dates |
Application Due Date |
Notes |
| January |
5/25/25-9/7/25 |
Not included in the count |
| May |
9/25/25-1/7/26 |
Included in CY 26 count |
| August or October |
1/25/26-5/7/26 |
Included in CY 26 count |
Calendar Year 2027
| Advisory Council Dates |
Application Due Dates |
Notes |
| January |
5/25/26-9/7/26 |
Included in CY 27 count |
| May |
9/25/26-1/7/27 |
Included in CY 27 count |
| August or October |
1/25/27-5/7/27 |
Included in CY 27 count |
Receipt dates:
9/25/2025-5/7/26 6 max
Receipt dates:
5/25-2026 -5/7/27 6 max