I've read these answers:
but some of them are pretty old, some of the links are dead, and I'm not sure if any applies exactly to my situation.
My former employer offers a 401(k) plan, to which I had contributed about 60% of the annual limit when I left that job around 60% of the way through the year.
For the remaining 40% of the year I am/will not be covered by any retirement plan. Can I contribute any deductible money to my traditional IRA?
The IRS website has a page for folks covered by a retirement plan at work and a page for those who are not, but no page for a person in both categories.