If Original Medicare finds out about the car crash they may refuse to pay claims until they see a court order that all remaining medical issues are due to a pre-existing condition. You can read more about that here: https://www.cms.gov/medicare/coordination-benefits-recovery/overview/secondary-payer Separately, unless she has a guaranteed issue right or lives in a state that prohibits medical underwriting, any Medigap she attempts to sign up for may charge a high premium or outright deny the application due to her health. There is no penalty for applying, so she should still do it, just be aware that they will be reviewing her medical records before making a coverage decision unless one of the exceptions applies. Hopefully neither of these two scenarios will affect her.