Thank you! The other person made it seem like I was the only one who couldn't find the answer from "the Google", lol. I now know that it's for balances over $50,000, but oddly enough, my client only owed about $42,000 and the IRS made her file the 433-D. So I don't know what was up with that, and that's what was confusing.

My main issue was that it isn't available on ProSeries (like the 9465 is), and that's a bit frustrating. Maybe they'll eventually change that. I get that there probably aren't all that many people whose past due balance goes over $50k, but it would be nice to have it available to provide to the client. While you can fill in the 433-D on the computer in PDF format, it doesn't line up properly and doesn't look very professional...

Good luck to you too, and thanks for your compassionate response 🙂