My hubby is in Assisted Living, is his monthly rent deductible for IRS?

See IRS publication 502 (on their website) for specific rules.

Husband was in rehab after breaking his hip and he was released because they didn't think he was progressing with phys therapy. Physical therapists and nurses all said I wouldn't be able to care for him at home since he was in a wheelchair. As far as I know, the doctor at Rehab didn't recommend where he should go.

If it was a doctor recommended move, it should be totally deductible, but you need to sit down with a tax consultant to be sure.