Yes. It's a deductible medical expense. From IRS Publication 502 re medical expenses:
"Qualified long-term care services are necessary diagnostic, preventive, therapeutic, curing, treating, mitigating, rehabilitative services, and maintenance and personal care services (defined later) that are:
Required by a chronically ill individual, and
Provided pursuant to a plan of care prescribed by a licensed health care practitioner.
He or she is unable to perform at least two activities of daily living without substantial assistance from another individual for at least 90 days, due to a loss of functional capacity. Activities of daily living are eating, toileting, transferring, bathing, dressing, and continence.
He or she requires substantial supervision to be protected from threats to health and safety due to severe cognitive impairment.