talk to a tax expert in your state-dh and i collectively have 4 different sources of disability income and some are taxable, some are not, some we receive 1099's on, some we do not. with social security it depends, in part, on the types and total amount of other sources of 'countable' income as to if the social security hits a taxable threshold. also with civil service disability pension there can be ENTIRELY specific tax laws (esp. if it's a service connected disability in which case some is entirely tax free). if your dh just started getting social security disability in 2021 and got a lump sum going back for prior years there are also ways for a cpa to look and see if your prior year's returns (for the years the lump sum covered had it been paid timely) should be amended to spread out the lump sum and avoid a big tax hit (this saved us immensely).
it is such a specific type of tax law that it's well worth it to have a trained professional do it for at least the first year or two (not the h&r block tables at the superstores).