I've tried finding the actual law online and am struggling. Then the Comptroller's office needs time to adjust the tax return (will it be a subtraction modification or what), and then they need to let all the software companies know, and then the software companies need time to change their programming. Bottom line, weeks or longer would be my guess. The prior reply is correct - you can't just flip a switch.
Yeah, I saw SJR mention that last night. I think this is as good as it gets for now. I suspect if you keep checking the link that will be the best way to see when it's updated. I tried finding other sources but all I was getting were one or two paragraph snippets from news organizations and some useless "public relations" videos from the MD government. The only mention I've seen of the $75K/$100K income cap on the unemployment subtraction is in the marked-up version of the bill.
Here is the info from the Comptrollers site. From the Governors site you can see the actual signing that took place on 2/15/21. I know it takes time to rewrite programs (I've done it in a past life), but we've known this was coming for about 6 weeks when he first announced it. Of course, I do understand that all these laws have been changing ridiculously fast. It's just frustrating having to hold up the returns. Hopefully it'll be soon!