Steve, thanks so much for your message. This whole business was incredibly frustrating, like you said. What I ended up doing was choosing to file by mail, then printing out the return that TurboTax generated, throwing away their Schedule H, and substituting the Schedule H that Care.com sent me. (I then made sure that the numbers on the 1040 were correct.) It felt odd to be mailing an actual paper return for the first time in years, but at least I was able to mail a return that was correct.
Anyway, there have to be lots of people in IL and other credit reduction states in this situation. Probably a lot of them just didn't notice the error. I've used TurboTax for a lot of years, but if they don't fix this problem, this is the last year. I'll take my business somewhere else.
