The borough is a county, and the county is the unit
People move between boroughs the way people elsewhere move between neighborhoods, and it does not feel like relocating. For Medicare purposes it can be, because you have changed counties. A move from Brooklyn to Queens is a county change even if your commute barely shifts.
The practical consequence is that a plan you are happy with may not follow you, and that a move can open a Special Enrollment Period you did not know you had. Both are worth checking against the new address before the move rather than after.
New York’s Medigap rules are genuinely unusual
Most states let Medigap insurers use medical underwriting once your six-month open enrollment window has closed. New York does not. Medigap policies in New York are sold on a continuous open-enrollment, guaranteed-issue basis, which means you cannot be turned down for a Medigap policy on the basis of your health history.
That is a real structural difference and it changes the shape of the decision here compared with New Jersey or Pennsylvania. It does not make any particular route automatically correct — guaranteed issue affects whether you can get a policy, not what it costs you or whether it suits your situation. But it does mean the "you may not be able to switch back later" concern that applies in most states applies differently in New York, and you should not take that warning secondhand from a national advertisement.
Specialists, referrals, and a city built on them
New Yorkers tend to accumulate specialists, and often ones they have seen for many years. That makes the network question sharper here than the premium question. Under Original Medicare, any provider accepting Medicare assignment can see you. Under Medicare Advantage, the plan’s contracted network and its referral rules govern.
I will not tell you from a web page whether a specific practice participates in a specific plan — that is plan-and-year specific and I would be guessing. It is checkable by name before you enroll, and for most of the people I talk to in the city it is the check that decides the answer.
Questions worth bringing to the conversation
- Which county is my borough, and what does that change?
- I am moving from one borough to another — does my plan follow me?
- How does New York’s guaranteed-issue Medigap rule apply to my situation?
- Are the specialists I have seen for years reachable under what I am considering?
- I spend part of the year outside the city. How is that treated?