I am getting dental implants this year that would cost $40,000. I know I can deduct anything of 7.5 of my AGI. Is there a maximum deduction?

[DoninGA]

No, there is not a maximum for a medical itemized deduction.

[xmasbaby0]

But .... do understand that itemized deductions can affect your refund or tax due to the extent that you either owe less or maybe get back some or all of the tax that was withheld from your income.  You will not get a refund that is more than the tax that was withheld based on a medical expense deduction.

[NCperson]

in essence, the deduction can not result in line 15 for Form 1040 to be less than zero.  That creates the limit. 

[Mike9241]

you can only deduct what you actually pay in the year. 

due to tax laws if you finance with the dentist, you can only deduct what you pay on the loan each year.

while if you put it on your personal credit card, you can deduct the full $40K