If you decide to leave Morgan Stanley, the money in your HSA is yours to keep. If your new employer offers a medical plan with an HSA, you should be able to roll over the amount from your Morgan Stanley HSA into your new plan. You should confirm with your new employer.
If your new employer doesn’t offer a qualified plan, you can still use your HSA to pay for out-of-pocket qualified health care expenses at any time. However, you won’t be able to continue making contributions to your Morgan Stanley HSA.