Will Social Security help me get a walk in shower?

The better thing to do, rather than worry about modifying your shower, is to get some physical therapy to help you address your physical decline. You don't have to accept every decline as just part of aging. Most times you can do proper exercises and work on skills to improve your function. If you are home bound you may qualify for home health services which would be paid by your part A Medicare. If you are not home bound you would have to get outpatient services which is billed through part B. Talk with your doctor about getting physical therapy services. A PT or an OT could recommend equipment or additional modifications for your home if you need them. In most cases Medicare doesn't pay for anything that happens in the bathroom.

No, and if they would, it would be through Part B, which covers out-of-hospital expenses and which you turned down. Part A only covers in-hospital expenses.

In Canada, yes. In America, I kind of doubt it.

sorry in wrong category I could not change in edit