His expenses would be deductible as Itemized Medical Expenses, but ONLY if you itemize.
Itemized expenses include mortgage interest, state and local taxes up to $10,000, medical expenses in excess of 7.5% of your AGI and casualty and losses in excess of 10% of you AGI with the first $100 not counting towards the loss. Your health insurance and all medical expenses are only deductible for the amount that is over 7.5% of your AGI. This means if your AGI is $50,000, then the amount that is over $3,750 is deductible.
Then your total itemized expenses would need to be greater than your standard deduction below in order to benefit from your service dog expenses.
The 2023 Standard Deductions are as follows:
Blind and MFJ or MFS add $1,500
Single or HOH if blind add $1,850
Standard versus Itemized Deduction
Medical expenses are entered in the deduction and credit section of TurboTax under Medical.
If the animal is truly a service animal (not just an "emotional support" animal) you can enter the expense as medical expense.
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 2023—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
2023 STANDARD DEDUCTION AMOUNTS
SINGLE $13,850 (65 or older/legally blind + $1850)
MARRIED FILING SEPARATELY $13,850 (65 or older/legally blind + $1500)
MARRIED FILING JOINTLY $27,700 (65+/legally blind) ) + $1500 per spouse
HEAD OF HOUSEHOLD $20,800 (65 or older/blind) + $1850)
Go to this IRS Publication 502 for medical expenses - https://www.irs.gov/pub/irs-pdf/p502.pdf
Guide Dog or Other Service Animal
You can include in medical expenses the costs of buying, training, and maintaining a guide dog or other service animal to assist a visually impaired or hearing disabled person, or a person with other physical disabilities. In general, this includes any costs, such as food, grooming, and veterinary care, incurred in maintaining the health and vitality of the service animal so that it may perform its duties.