“As with Part A, the Part B premium doesn’t change across the states”
https://www.ehealthinsurance.com/medicare/cost/will-moving-increase-my-medicare-premiums/
That has always been my understanding.
PLANS, not Parts, C, D, G and N are supplemental plans all having the same benefit supposedly but different administrators and costs vary greatly by the carrier. Plan F is not available any longer but some still have it if they are grandfathered.