Must all funds in joint accounts be disclosed to nursing home on application?

Any asset of which the applicant has any incidence of ownership must be disclosed.
If it can be demonstrated that a portion of the value of a joint account was contributed by the joint holder then that portion may be excluded as a a countable asset. Otherwise, the full value of the joint asset will be attributed to the applicant.

DM -Yes you need to report all assets and income. Joint accounts are sticky to deal with for Medicaid and also SSA has issues with SS checks going into accounts that are "co-mingled" which these likely are.

What I'd suggest you do is really take a step-back and go over your dad's total financial history and then also what the co-owner's situation is. Medicaid rules are set by each state and so you need to find out what your state's limits are for income & assets. In general, it's 2K for income and 2K for non-exempt assets.
But again you need to see exactly for your dad's state, like my mom is in TX and TX income is $ 2,094.00 (2011), so it varies and could or could not make a big difference in qualifying for the financial aspect of Medicaid.

My experience in dealing with Medicaid in 2 states, is that there are 2 levels of review. The first is the NH and they will give you a page (or 2) of items that they need copies of that they review (1st level review) and in turn these are included with the NH application to the state for the state to pay them and for the resident to be reviewed. The NH is looking to see if mom or dad is OK to accept in their NH as "Medicaid Pending". Pending is critical because if the NH doesn't like what they see in what you provide them and they can sense there will be an issue - then the NH can require a deposit or private pay until Medicaid approves the application.

Now the state in it's level 2 review can do a complete financial on a person via their SS #, their late spouse's SS #, tax stuff, all tangible property ownership tied to their names, etc. And when they apply for Medicaid, you or them sign off for basically an all-access pass to their financial history. Some states have reviews done by state employees and other states have contracts out with companies that specialize in compliance and fraud. HMS does Medicaid recovery for many states and they have extremely sophisticated algorithms to sniff out patterns of fraud. They are super on details and kinda ruthless and will find stuff out eventually.

I'd be concerned for the person who jointly holds the account too. Say there's 20K in it and in reality the initial $ was theirs but your dad was put on it as an emergency signer. They will be very unhappy if the state takes the position that the 20K is your dad's. Or dad goes into the NH and all is OK for Medicaid, and then the co-owner dies and dad now has inherited the 20K and then becomes ineligible for Medicaid and you get caught up in penalty issues for not disclosing.

For my mom, the level 1 review required 3 years and 6 months of bank statements including a notarized on bank letterhead statement from the banks as to the disposition of any and all accounts, CD, Tbills, etc she owned or had an interest in. My mom's application submitted to the NH with documents was about 100 pages. Mainly due to the old-school life insurance policy she had, which was about 25 - 30 pages in an of itself front and back, legal size. She had been in IL prior to NH (no AL), and also still had a home, so her finances showed a clear pattern of where her $$ went. State also look for deposits that aren't their SS or other regular recurring retirement or income. If there's something like that, you may have to validate why that source of income. If it's a annual amount that takes them above Medicaid limit for that month, then you have to ask to do a special form to amortize the amount over 12 months so there is no issue. My mom's life insurance policy is so old and paid up, so it actually pays her an annual dividend which takes her just above the limit for that month, so I had an extra form to deal with.

It is at the 2nd level of review - by the state - that a transfer penalty gets to be an issue. Remember they have an all-access backstage pass (and NO you do not get the cool I'm a roadie with the band T shirt) and stuff will show up and trigger a transfer penalty possibility. For us, it was an car that was just within the 5 year lookback that caused a transfer penalty issue. I got it resolved within a couple of weeks, so never had to deal with the dreaded "30 Day" notice from the NH other than to say it's been worked out, so back off. Remember all property ownership is recorded by the state and they will be able to match stuff up. You really want to do whatever possible to be accurate in full on the application and not stuck in dealing with a transfer penalty issue with mom or dad in a NH @ 5K - 10K a month that you could be liable for.

The only thing that seems to be under the radar is mineral rights. This is probably due to how they are written up and recorded (the whole "undivided 3/1580's of over-riding royalty in & to the land......etc) which is total loco to figure out.

If the accounts were jointly owned by your mother and father, then he should have became the sole owner at the time of her death. Were there any unusual conditions on the accounts that would have kept that from happening? If there was, who is on the accounts now with your father?

If you don't disclose all funds and they find out, you are in trouble. Medicaid fraud if they would chose to charge you carries a 10 year prison term. They use his social security number, so if that is tied to these accounts, they will find out about them. If he has too much in these accounts spend them down on acceptable items, keep the receipts. Any work he needs by the dentist, hearing aids, new eyeglasses, clothes, repairs on his home or car. and so on. If the accounts are an inheritance to him then they would be considered. If you are doing private pay then you don't have to disclose them, however if you and the nursing home will be filing for Medicaid, then yes. They will use the information you give them to figure out if he will qualify for Medicaid. If you don't give them all the information and he is denied then he will be responsible for the money they are owed. Medicaid can be retroactive in benefits.