We cannot see your tax return so we can only make guesses. One guess---did you pay for Medicare from Social Security benefits that you received? If so, when you entered your SSA1099 and entered the amounts paid for Medicare the amounts automatically flowed over to medical expenses.
I paid for CHIP for my children out-of-pocket, along with Obamacare for my joint-filer and myself. The 1095-A expenses show up in the proper place. I don't remember entering anything regarding CHIP/Medicaid that may explain this. Is there a section for CHIP/Medicaid payments?
It depends. Some of the deductions are automatically transferred over to Schedule A as itemize deduction which includes premium paid to Health Insurance Marketplace from form 1095-A, state and local income taxes from form W2, and Medicare B,C, & D premium payments from form 1099-SSA (retired taxpayers only). Eligible taxpayers use Schedule A to figure itemized deductions. In most cases, federal income tax will be less if you take the larger of your itemized deduction
My understanding of what you've said is that it doesn't really matter if there is an erroneous amount here, because it is an itemized deduction, and does not matter if I'm taking the standard deduction. It would only matter if I wanted to itemize. Is that correct?