CMS sent letters to Medicaid consumers who received tax credits to purchase insurance through the ACA marketplace. The agency says these people have to terminate marketplace coverage and pay back the amount of the credit they've received. A CMS spokeswoman declined to say how many people fall into this group only noting it was "a small number." The issue exists in states that used the federal marketplace, HealthCare.gov, not those living in state-based exchanges. Consumers are finding themselves being dually-enrolled if they've experienced a life change, like a drop in income that made them eligible for Medicaid after they had purchased marketplace coverage. Similarly, consumers who are enrolled in marketplace coverage may have applied and been awarded Medicaid coverage while failing to terminate a marketplace plan. The notice tells consumers the onus is on them to cancel their exchange plans, something people may not have realized.