My husband has to repay 83,303.70 in disability ($300 per month for 240+ months). Will I be liable when he dies?

Always a good thing to those that defraud the taxpayer get their comeuppance.

Use some of that stolen $83k on a lawyer, you’ll need it.

Social Security recently updated (and lessened) the repayment amount rules. This is to reduce hardship from the payments.

Here is a Press Release from the Social Security's blog, from March of 2024.
https://www.ssa.gov/news/press/releases/2024/#3-2024-5

Press Release
Friday, March 29, 2024
For Immediate Release


Mark Hinkle, Press Officer
press.office@ssa.gov
News Release SOCIAL SECURITY
Social Security Eliminates Overpayment Burden for Social Security Beneficiaries
Automatic Overpayment Recovery Rate Reduced to 10 Percent
The Social Security Administration announced it will decrease the default overpayment withholding rate for Social Security beneficiaries to ten percent (or $10, whichever is greater) from 100 percent, significantly reducing financial hardship on people with overpayments.
“Social Security is taking a critically important step towards our goal of ensuring our overpayment policies are fair, equitable, and do not unduly harm anyone,” said Martin O’Malley, Commissioner of Social Security. “It’s unconscionable that someone would find themselves facing homelessness or unable to pay bills, because Social Security withheld their entire payment for recovery of an overpayment.”
The agency works to pay the right people the right amounts at the right time, and Social Security issues correct payments in most cases. However, there is room to improve, as people count on the agency to prevent overpayments from happening and make it easier to navigate the recovery and waiver processes when they occur.
When a person has been overpaid, the law requires the agency to seek repayment, which can create financial difficulties for beneficiaries. As of March 25, 2024, the agency will collect ten percent (or $10, whichever is greater) of the total monthly Social Security benefit to recover an overpayment, rather than collecting 100 percent as was previous procedure. There will be limited exceptions to this change, such as when an overpayment resulted from fraud.
There will be a short transition period where people will continue to experience the older policy. People placed in 100 percent withholding during this transition period should call Social Security’s National 800 Number at 1-800-772-1213 to lower their withholding rate.
The change applies to new overpayments. If beneficiaries already have an overpayment with a withholding rate greater than ten percent and would like a lower recovery rate, they too should call Social Security at 1-800-772-1213 or their local Social Security office to speak with a representative. If a beneficiary requests a rate lower than ten percent, a representative will approve the request if it allows recovery of the overpayment within 60 months – a recent increase to improve how the agency serves its customers from the previous policy of only 36 months. If the beneficiary’s proposed rate would extend recovery of the overpayment beyond 60 months, the Social Security representative will gather income, resource, and expense information from the beneficiary to make a determination.
Social Security launched a comprehensive review in October 2023 of agency overpayment policies and procedures to address payment accuracy systematically (See Learn about Overpayments and Our Process | SSA and Press Release | Press Office | SSA). This procedure change is a direct result of the ongoing review. This change and the adjustment to 60-month repayment are part of four recently announced key updates to address improper payments (See Press Release | Press Office | SSA for more information). The agency also is working to reduce wage-related improper payments by establishing information exchanges with payroll data providers that will significantly reduce the number of improper payments, once implemented (See Press Release | Press Office | SSA for more information). The agency will continue examining programmatic policy and making regulatory and sub-regulatory changes to improve the overpayment ...

(all I could copy of it

I quite agree that you need professional help, but first check if there is a class action going already. If so join in, rather than taking it on yourself. The Ombudsman has the advantage of being free to approach, but a lawyer would still be a big help. Ignorance of the law is not a defense, but 'fairness' may be different if your ‘ignorance’ stemmed from the fact that they weren’t auditing so not doing their own part of the deal.

Unfortunately, our courts doesn't accept "ignorance" of the law as a defense for actions or decisions. This is why you need a professional to helpl you through this.

I agree, you need to consult with an elder lawyer.

And I am sorry, but when on SS disability, you are capped at what you can make a year. I think its about 17K. Your husband should have been made aware of this when he started receiving SSD. It was up to him to keep track of his earnings.

I so hope you cannot be held responsible.

You are talking 100K here, and so you should see an elder law attorney.
This is not DIY.
You cannot afford to be wrong and cannot rely on a Forum of strangers to advise you.
You need the facts and all options laid out for you.
I truly wish you the best of luck.

The math here makes absolutely no sense. 240 months would be 20 years.

This is hard to understand. If DH ‘worked too many hours in April 2020’, it seems strange that over-payment could have created a debt of over $83,000. Did he also work too many hours for the rest of 2020? Was there something special about his work that made it compatible with his disability, so that it was easy to keep going longer? Was he poorly paid, so that working was only viable with the disability payment as well? Did you both realise that he was going over the hours limit, or was that hard to work out? If the normal audits had happened, would he have changed his hours so that he wasn't in breach? Could he repay it, without it coming from what you are now earning?

If there were reasons along these lines that make it unfair to pay back the money, I think it’s worth taking it to the Ombudsman. The purpose of the Ombudsman is to question Government actions that are unfair. I would guess that other people have been caught too, and I would Google to find if there is a body or group of some sort which is taking on the problem. Fighting the Government is not something to do on your own!

What a nightmare, and now to be dealing with this on top of his illness. I’m so sorry.

I hope people here might have some information or experience to share with you, but it sounds like a situation when it would be worthwhile to get guidance from a lawyer specializing in this area (I assume employment law).

Best to you!

Social Security Handbook

1906. Liability for Repayments
1906.1 Who Is Liable For Repayments?

A beneficiary and/or a representative payee receiving retirement, survivors or disability insurance, benefits on behalf of a beneficiary or SSI, may be equally liable for repayment of any overpayment received, as follows: 

The beneficiary is liable if he or she received the benefit of the monies; 
The representative payee is personally liable if he or she: 
Was at fault in creating the overpayment; or 
Did not apply the monies for the beneficiary's use and benefit.

The answer seems to be yes. I would discuss this with a CPA.