You don't need to file Form TC-40D with your return. Simply keep this form and all related documents with your records. For more information, please see Form TC-40D, Dependent with a Disability Exemption.
Form TC-40D has been eliminated because the state of Utah decided to give a personal exemption for "dependents that qualify for the child tax credit on a filer’s federal return". Disabled children qualify for that credit, so there is no longer a need for the TC-40D.
In 2017 Congress passed the Tax Cuts and Jobs Act, suspending federal personal exemptions and increasing the standard deduction for individual income tax. The federal standard deduction (line 12) is greater than previous years. Meanwhile, the 2018 Utah Legislature passed HB 2003, creating a Utah personal exemption for dependents that qualify for the child tax credit on a filer’s federal return."
[Edited 8:06 am | 1.28.2019]
Thank you for answering but to clarify...this is as simple as "Utah no longer allows an ADDITIONAL exemption for having a dependent with a disability?
That's correct. And please accept my apologies for not providing a better answer in the first place.