I have $20k of medical at $100k income and turbo tax says take standard deduction

MEDICAL EXPENSES

The medical expense deduction has to meet a rather large threshold before it can affect your return. The amount of medical (including dental, vision, etc.)  expenses that will count toward itemization is the amount that is OVER 7.5% of your adjusted gross income. You should only enter the amount that you paid in 2024—do not include any amounts that were covered by insurance or that are still outstanding.  Of course, your medical expenses plus your other itemized deductions still have to exceed your standard deduction before you will see a difference in your tax due or refund.

To enter your medical expenses go to Federal>Deductions and Credits>Medical>Medical Expenses

2024 STANDARD DEDUCTION AMOUNTS

SINGLE $14,600    (65 or older/legally blind + $1950)

MARRIED FILING SEPARATELY $14,600    (65 or older/legally blind + $1550)

MARRIED FILING JOINTLY $29,200    (65 or older/legally blind + $1550)

HEAD OF HOUSEHOLD $21,900    (65 or older/legally blind + $1950

Sorry.   You can only deduct the amount that's OVER 7.5% of your AGI.  So it might take a lot to be worth entering. And then all your itemized deductions have to be more than the standard deduction to get any benefit (so you would only be getting the benefit of the amount that puts you over the standard deduction). And since the Standard Deduction is increased more people will not need to Itemize.

For 2024 the standard deduction amounts are:

Single 14,600 + 1,950 for 65 and over or blind (16,550)

HOH 21,900 + 1,950 for 65 and over or blind (23,850)

Joint 29,200 + 1,550 for each 65 and over or blind (30,750/32,300)

Married filing Separate 14,600 + 1,550 for 65 and over or blind (16,150)

Health care insurance premiums, including dental and vision insurance premiums, and other medical expenses that you paid with out of pocket funds and were not reimbursed are an eligible medical expense that you can deduct using Schedule A for itemized deductions. However, only your total medical expenses that are greater than 7.5% of your Adjusted Gross Income (AGI) can be deducted. Your total itemized deductions reported on Form 1040 Schedule A must be greater than the standard deduction for your filing status to have any tax benefit.

Standard deductions for 2024

Single - $14,600 add $1,850 if age 65 or older
Married Filing Separately - $14,600 add $1,550 if age 65 or older
Married Filing Jointly - $29,200 add $1,550 for each spouse age 65 or older
Head of Household - $21,900 add $1,950 if age 65 or older

So, only $12,500 of your medical expenses are entered on Schedule A as an itemized deduction, based on the numbers you posted.

$100,00(*)7.5%=$7,500

$20,000(-)$7,500=$12,500