I've dealt with all of those things - except Medicaid - with my Mom in 2016 and now with my Dad.
Depending on your employer and your own financial picture, you could look into taking some leave from work under the Family Medical Leave Act (FMLA). It's unpaid time off, you can take it in any increment or pattern you need to, and they have to offer you an equivalent position when you return. It applies to many but not all employers/employees.
To the extent you can and it makes sense, simplify and consolidate their finances. Combine accounts as much as possible - if they have five savings accounts, get them down to one good one. If they have four credit cards, get them down to one or two. If they have retirement plans at seven different places, get them down to one or two. This will lessen what you need to track and manage.
If you like automation (I do), automate what you can. Automatically pay their bills - mortgage, credit card, Amazon account, medical bills. I still track everything, but the automation is one less thing I have to do.
Depending on how aggressive, your parent may qualify for hospice care under Medicare/Medicaid. It is basically free and provides some good benefits, and depending on the circumstances it may mean better care for your parent at a lower cost for things like medications (because they will possibly stop some medications). We did hospice care with my Mom the last year of her life and it was a great experience (relatively speaking, of course, she still passed away). We're starting hospice for my Dad now.
On the POA, you'll hear people talk about bad experiences, but mine have been mostly good. I would recommend scanning the signed POA into an electronic PDF copy. Make a list of financial institutions your parent deals with, and just pick them off one by one. Usually they'll let you email a PDF of the POA to them. Once they get it on file, then it's easy to deal with them - "Hi, I have a POA for my Dad and I need to do X with his account". Some medical places will require a fax because of a medical privacy law called HIPAA, but there are web sites out there that will create and send a fax for you for a few bucks.
While you're at it with the POA submissions, if it's OK with your parent, I would change the email / phone / mailing address on everything to come to you instead of your parent. Expect this to take a while. File a change of address with your parent's local post office to send everything to you; anything that shows up with a yellow forwarding label is another task to get the address (and email and phone) switched.
I don't know much about Medicaid lookbacks - I don't believe them enjoying their money a little or vacations would be an issue. I also doubt them paying for you to join them on a trip, especially if you're helping with mobility issues, would be an issue.
Taxes - with increased medical bills, it's possible that your parent may be able to itemize on their taxes and save a little there. Generally, medical expenses in excess of 7.5% of AGI are deductible on Schedule A, and if their Schedule A itemized deductions exceed their standard deduction, there can be tax savings. In particular, if they are living in a medical facility (such as assisted living or memory care) and a primary reason for them is for medical care, then the entire cost of room and board is a Schedule A medical expense.
In terms of recordkeeping, a couple of thoughts:
1. I get all of my Dad's Medicare EOBs sent to my address. I file everything in a bill folder in chronological order by date of service. I cross check medical bills against the EOBs. I go through it about once a month and pay any outstanding bills (if they're not already autopaid; most are).
2. I also keep a document of my Dad's discrete medical issues which I review on about a weekly basis now. It helps keep me organized - When did the nurse mention hospice? When was that UTI? What medication was he given? Did I tell my sisters about his most recent fall? - so I can follow up on anything. Over time, it also helps paint a larger picture which we can use for more complicated medical care and follow up on those patterns.
3. For taxes, I keep track of medical expenses in an Excel spreadsheet and copies of the supporting documentation in a taxes folder. I transfer the medical bills from the bill folder to the tax folder and add it to the Excel spreadsheet when I pay the bill.
Go through your parent's advance directive with them and that you understand what their wishes are. If it goes on long enough, try to check back in with them to confirm their wishes are still the same. My Dad has a paragraph in his that fairly specifically addresses his current medical state, and it's very comforting to see my note that I confirmed his wishes in that paragraph about two years ago and so we know what he wants. If you can, try to pre-game with your parent's medical providers what the most likely outcomes are and make sure you know what your parent's wishes are in those possibility spaces.
Take care of yourself. Caregiver burnout is real, and not good for anyone. There are organizations out there which will provide respite care for you. Or lean on other family if you can and they are willing.
You might pre-grieve and start the grieving process of losing them before you actually lose them. I believe this is OK and a good thing even. You might not even be that sad when they pass away because you've already done all or most of the work.
Sorry you're going through this. It can be really rough.
