My Dad has spent all the money and he now needs to go to a nursing home. Will they deny him Medicaid?

It won't count if he used the money for his living expenses; rent, food, medical etc. If he gave away large portions this may pose a problem. If he can produce bank records for the past 5 years he should be ok.

Medicaid is very good at finding out where the money went. They will look at every financial deal, check written and gifts sent for the last five years, credit cards tax returns etc. They can probably even tell you what color underwear he buys. So if he gave it to family, guess what? Family now gets to foot the bill for his care.

If he spent his money on his own needs and wants, no problem. If he has given it away or send his kids on a cruise or paid his grandkids' tuition, there may be a problem.

What did he do with the money?

Not if he used the money for his senior housing, food and medical.