If your doctor writes a prescription for a wheelchair then yes Medicaid or even Medicare will cover the cost of a wheelchair.
The wheelchair must be approved by a doctor saying that you require a wheelchair to properly get around with otherwise Medicaid or Medicare will not pay for it.
But if the doctor approves it for Medicare or Medicaid they will usually pay for it.
Medicare and Medicaid will usually also pay for a power wheelchair or mobility scooter as long as your doctor says you need one.
If you're a veteran the VA will also usually pay for and provide you with either a wheelchair or mobility scooter or power wheelchair.