If my mother is in a nursing home and has LTC Medicaid, do I need to keep her Part D prescription plan?

Is Mom in home permanently?  Medicaid is paying for her care?  If so, Medicaid is probably covering her health Care insurance too. Talk to the admissions clerk to see if Mom is covered for precriptions. If she is there permently than Medicaid should cover it.

Do you mean Medicare? I don't think that Medicaid kicks in until the LTC policy is depleted. I think she will still need part D for prescription coverage.