What can nursing home do with "left over" money?

Many places proactively send out statements to the POA informing about the fund balance so that the balance won't get too high and it's also a form of good communication with the patient's family.     I agree they should be able to provide a detailed accounting of what was spent and when.   Why you weren't contacted would be another issue.

The snf had to provide an accounting monthly as to how monies were spent - or not spent. My spouse did not have VA or SS involved as he was a straight Medicaid case. Personal funds could be used for anything the person wanted as long as he had the money to spend. In our locale, facilities are too short staffed to send more than a couple designated persons to shop for residents a couple times monthly. That was an issue I inquired about before placement into the local facility. Direct care staff (who typically know best what personal items are actually needed) had to ask for monies to be spent on behalf of residents, but they did not handle the shopping or the money.

If the facility was not informing you of such purchases, the accounting office should be able to give you copies of account statements that reflect these purchases on his behalf. The statements would reflect the balances each month.
If you were his FPOA, you should have been notified all along the way.

Those funds are called a Personal Needs Acct. Now Dad has passed, they become part of his estate. Even if not a Will, I would go to the Probate Office and ask about a certificate that gives you the right to handle Dads finances. If he has any money in his acct from the spenddown is also part of the estate. That money does not go back to the State or to the NH. Here is the government info.

https://www.cga.ct.gov/PS99/rpt%5Colr%5Chtm/99-R-0025.htm

If what u say is true, this NH needs to be reported.

Sorry about his belongings. I went back to the home the day after Mom died and got everything out of her room. I was told the things in the laundry I could pick up the next week. Never happened. Kept being told there was nothing. And I was known by the staff and the laundress.

I think you are referring to the Resident Trust account. When the account was opened someone probably had to fill out a form or contract. You need to ask the admin for this, if you are the executor of your dad's estate. You may be able to ask for an accounting of how the funds were spent, but not sure. I am pretty sure Medicaid (if he was on it) doesn't touch it after death.