Yes, when filing Married Filing Jointly (MFJ), both spouse's income are included when calculating the $32,000 threshold for SSDI being taxable.
You may be wondering if filing Married Filing Separately (MFS) is going to save you money, because you won't have to add your spouse’s income to your return. It usually won't. There is a special rule that says SS becomes taxable at zero ($0) other income when Filing as MFS. The doubled standard deduction, for MFJ, will usually wipe out most of the spouse’s income, on a joint return. But you will still get the use the lower joint filing rates.
