I may be a step-mom but I’m a full fledged wife of 35 years. Hubby diagnosed w/Alzheimer’s, moderate-severe. Step kids run right over me.

It is time to seek an elder care lawyer now, you and your husband. I am praying if you paid on this home that your name is on the deed. You need guidance now that has no stake in the game. If your husband doesn't want to do this, and says "The kids will handle all this" then YOU need to go on your own. Take a list of all assets and the name/s on the assets.
There honestly is no other answer now, particularly with step kids planning away with a Lawyer already IN the family. You say there is excellent health "except for Alzheimer's and glaucoma and osteoporosis". Quite honestly, that not excellent health. You need good guidance now, and may need to make a Fiduciary your POA to handle finances, division of finances if one needs care before the other, and protection of assets for the two of you.

Your husband can’t write a new will because of his moderate-severe Alzheimer’s. So forget about that. If you think the new will was written under duress, you can hire a lawyer & challenge it but it’s going to be difficult to prove unless the Will was written after his diagnosis & there are medical records documenting his competency at the time the Will was written.

What Alva wrote, 100%. My husband comes from a post-divorce blended family when he and his brothers were in middle school. The divorce was ugly (too much drama to elaborate on here) and after decades an emotional wound was scabbed over but never fully healed for 2 of my brothers-in-law. When their dad (my FIL) died, these 2 BILs were astonished that they didn't get an inheritance. My FIL wisely created a trust and made my DH and the most well-adjusted step-brother co-trustees to ensure that the step mom was protected financially and prevent infighting. There may well be an inheritance, but not until step mom passes. Unfortunately, one cannot underestimate the unhealed wounds and dysfunction that can be created in blended situations, even if you were the world's most perfect stepmom. Your husband is not putting you first, and this may be residual guilt from whatever the circumstances were that created the blend. A wise, experienced elder law/estate planning attorney can come up with a solution to mitigate future financial and emotional disaster and will be well worth whatever the cost is. You're not the first people to have this challenge. Do act to protect yourself if he won't.

Bonnie; my ex has been re-married for nearly 20 years. His will states that his wife gets all of his retirement benefits, but that his/our children inherit what remains after she has passed.

I'm curious what you and your husband discussed when this will that son in law wrote was made. Was there a conversation about what you might get?

Were your own earnings lessened by marrying him? What are your SS benefits likely to be (both your own and spousal benefits).

WWW.Bogleheads.org is a grea place for financial advice.

Bonnie has yet to answer anyone's questions. There's little point in making assumptions or declarations about what may or may not be possible.

My SON is a lawyer and did we use him as ours?

ABSOLUTELY NOT!!

DH fought me on this for years, until I simply called a lawyer I knew and trusted and started the paperwork. Long story short, I made it happen, and when we sat down to finalize everything, DH reluctantly agreed it was better to NOT use our out of state son---he's a little bulldog, not very nice, and I didn't want him to know all the ins and outs of our business. He lives 1000 miles away and pretty much has no clue what goes on in our day-to-day. He'd drive his sisters crazy if he were executor and/or had handled the will. My OD is executor, 2nd OD is 2nd in line. Son doesn't have anything to say or do about our wants and wishes. It's best this way.

We're set up to live independently, as long as possible, but neither of us have 'longevity' in the genes. He is a liver transplant recipient and I just beat cancer. If I get 20 more years, it will be a miracle. DH probably has 15 or less.

Our lawyer asked if we wanted to A: live comfortably on our own or B: leave the 5 kids a very nice chunk of change.

Duh. We opted to take care of us. IF there is anything left over, the kids will know what to do, as per the will.

IMHO, NOBODY should 'expect' an inheritance. Did you earn that money? If not, you're not entitled to anything.

Even with his'n'hers families--I don't know. each case is different and the dynamics should be addressed in a will/trust.

No matter how a will is written, somebody will be mad, that's a for sure.

Son HAS done the wills for his wife's family--they are mixed with plenty of divorces to go around. Nobody has died yet, but he fears the hot mess that will ensue when they do.

Other things to consider:

Undue influence: You can move to have the will declared invalid if your attorney proves in court that it was procured by undue influence. Undue influence usually involves someone who occupies a position of trust, such as an adult child, who is manipulating the vulnerable person to leave all, or most, property to the manipulator instead of to those who would have been expected to receive it i.e. you, the wife of 35 years. In other words, the will accomplishes the manipulator’s goals rather than the goals of the will-maker.

Improperly executed wills: A will must be dated and signed in the presence of at least two adult witnesses, who also signed the will. In most states, the witnesses cannot be people who are named to inherit property under the will. Who witnessed your husband's will?

How old is the will your lawyer step son wrote for his father?

Who did your husband list as the beneficiary on his investments such as savings accounts, retirement plans, life insurance, etc.?

You need to ask an attorney a lot of questions. Before taking your husband along with you to an attorney, I think it would be wise for you to have your own personal consultation considering what your stepson did, which I find appalling BTW.

Bonnie, is the son who drafted the Will an elder law or estate planning attorney?   If not, then (and based on my experience), he may not be up to standards on end of life issues, including spousal protection.  That's not an excuse; it's a suggestion that putting it bluntly he may not know what he's doing in terms of marital common sense as well as estate planning standards.

Beyond that, I wonder how much influence he may have exerted over your husband.  And, I assume this was your husband's Will and not a joint will by the two of you?   If this is true, do you have your own Will, and other end of life documents?

If this is in fact your husband's desire, I too would get a will done, ASAP, just to be on the safe side.   And you don't need to consult your husband before you do this.

I agree with Alva on the issue of health; glaucoma can be a real threat to independence as well as care issues.   

But I would confront your husband before doing anything, just to assess his position and know where you stand.

There's another possibility and that's that your husband may need care before you do.    If his Will stands, and he's firm that he won't provide more for you, I'd think not twice but just once on whether or not I'd stay in the marriage and provide free care for him. 

Do you have children from your marriage, besides those from his other marriage?

I just realized something I completely missed when scanning your post:  your husband has Alzheimer's, "moderate-severe."   He may NOT have been mentally qualified to create the Will that provided you with little of his estate.

If so, there's a question of the validity of the Will.

When was he D'X'ed with Alzheimer's?   Before or after the Will was made?