How it will affect the SSDI is a question you need to ask the SS administration directly however here is a reference to read: https://www.sagesettlements.com/blog/2018/november/will-a-settlement-affect-disability-benefits-/
Individuals who receive Social Security Disability (SSDI) have essentially met eligibility requirements by paying into the social security system and being classified as disabled by the Social Security Administration’s standards. A personal injury settlement will not affect SSDI benefits.
As for taxes :
IRS Regulations
According to the IRS, any lawsuit settlement proceeds that a court awards for physical illness or injury are non-taxable. This includes wrongful death settlements, since the damages are imposed due to a court’s finding that a third party is responsible for the physical illness or injury that resulted in death. To qualify for this exception, the settlement must be compensatory, meaning that it must be a form of compensation for the pain and suffering caused in the case.
Since compensatory proceeds are non-taxable, they have no impact on a federal tax return. However, if there are any additional proceeds that are awarded such as punitive damages, payments for emotional distress, or awards for lost wages, those payments are considered income and are subject to income tax. Punitive damages are additional financial awards that a court may give to the family of a deceased or injured person in cases where the company or individual responsible for the death showed gross neglect or disregard.
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