I have been there, done that for Maryland and I had KPMG advising me and here is what I was told:
Maryland is among the most restrictive jurisdictions in the US for trying to capture expat income for income tax purposes. You cannot retain
a Maryland residence (even rented)
a Maryland registered automobile
any Maryland real estate
a Maryland postal address
OR
(and this is a REALLY big deal for the state of Maryland:) a Maryland driver's licence.
There was a couple who had personal effects in storage in Maryland for ten years and, when they returned to Maryland after that period, were adjudged liable for back taxes and interest and penalties over that period, although they had no other connections with Maryland. They had been living in Dubai or somewhere like that. As I recall, it was a substantial amount of money.
You also must clearly meet the residential requirements to be an expat (your tax advisor can give you the details).