@lmoser325, While there isn’t an actual cutoff age for SCT/BMT or CAR-T therapy, the process can be challenging for older adults. I was 65 at the time of my bone marrow transplant. I’ve mentored patients well into their 70s.
@cdsarmiento has shared that her husband had CAR-T at the age of 84 in 2022 in this reply: https://connect.mayoclinic.org/comment/1099324/

So you can see the age varies by individual. There are several factors your doctor will take into consideration to help you make the best decision for your health.
I found a good article from Dana Farber Cancer Institute that discusses transplantation in older patients. This might give you some insights into guidelines used in determining a prospective transplant patient’s eligibility. https://blog.dana-farber.org/insight/2016/10/stem-cell-transplants-rise-among-older-patients/

What has your doctor recommended in terms of transplantation? A stem cell transplant or CAR-T?