Do joint checking accounts pass to me at Mom's passing or would the courts consider these "convenience accounts" making the joint accounts part of her estate?

The joint accounts pass directly to you without going through probate. My mother put me on her accounts (over a 100K) as joint owner with right of survivorship. Now that she is dead, that account belongs to me which has made my step-father very mad. This was true of her investments of over 300K as well.

I have a different response than those above. Go back and look at the titles on the account. If it is 'joint' then half is considered your money and half your Mom's (even if it is really only her money). JTWROS (Joint with rights of survivorship) is different and it passes to the surviving person immediately.

With a diagnosis of dementia, the account titles can't be changed by your Mom. Lesson to all of us, a regular review of our own financial instruments and Wills should be made to be sure they properly reflect our wishes is important!

My best guess is that this will come down to how the accounts are set up. if the bank accounts are in her name and her SS # is the identifier on the accounts, then they are her's. If this is the case, I'd suggest that mom put you on the account so that the account(s) are POD to you. Pay On Death. POD accounts do not pass through probate either (nice!) and therefore you can go an empty them upon her death. Well perhaps not empty them, just in case SS does a clawback.

The bank can do the POD, it should be a standard form for them. You want to make sure that mom can showtime to make this happen @ the bank too. She will have to sign off for the POD and the bank officer will likely require that she is in his or her office without you…just to make sure this is what she wants. If mom has about 100K, then she likely has someone @ the bank who is her bank officer or has a relationship with. I'd call them and set an appointment to do this. POD's are pretty routine.

You stated,(I am an adult child for my 98 year old mother, caregiver, and POA)
If your ,your Mother's POA?Your not allowed to be on your Mother's bank account as Joint.POAs are not allowed to have a joint account together.
Read the dos and don'ts of a POA online?
By you being on your Mother's bank account as Joint account?Your POA can be revoked.You as your Mother's POA is not allowed to transfer funds from one account to another or barrow,gift or donate.You shouldn't be joint with your Mother's accounts.As POA your job is to record all transactions and account for all funds spent.You better contact your attorney if you state your joint on the account with your Mother?Your job as a POA is to sign checks as John Doe by POA.Not to be Joint on her account.If your Mother is not compatent It can't be changed.Your Mother should of placed this money in a trust.Does your Mother have a Living Will?Who is the exectators of the living Will?

JT - if mom's creditors do a charge off on the debt, be sure to be on the lookout in January, 2014 and future January's for a 1099-C, which it "Cancellation of Debt".
It is reportable and taxable income as far as the IRS is concerned. The creditor can issue it for the amount due plus fees & interest. It may not be for the tax year it was written off either (lots of fun there!)

1099 - C's information on-line are kinda geared to foreclosures or short sales and for real estate there are all sorts of deductions to off-set the "income" shown in the 1099-C. But for written off CC debt, you don't have that, so it is all income. The fact that it is totally phantom income doesn't matter, it's still taxable. If mom gets a 1099-C, you probably want to see a tax pro to get her taxes done so that she shows impoverishment. So that she has no income. 1099-C's can cause problems with Medicaid or other income based eligibility programs because it shows "income" which is the amount of debt written or charged off by the creditor