Quick answer: no portability, but Maine's own QTIP election gives married couples a real, separate planning tool. Run your own numbers in the Maine estate tax calculator.
Each spouse's exclusion stands alone
Maine does not let a surviving spouse add a deceased spouse's unused exclusion to their own. If the first spouse to die leaves everything outright to the survivor without any planning, that spouse's own $7,160,000 exclusion goes entirely unused, with no way to recover it later.
The Maine QTIP election, confirmed directly by the state
Sized precisely to the federal-state gap
That $7,840,000 ceiling isn't arbitrary — it's exactly the difference between the federal exclusion amount (net of any deceased spousal unused exclusion the decedent already used) and Maine's own exclusion. The election lets qualifying property defer Maine tax until the surviving spouse's own death, functionally covering the exact gap between the two systems.
The deferred property resurfaces at the second death
Property covered by a Maine QTIP election isn't exempt forever — when the surviving spouse later dies, their own Maine estate tax return must include the current value of that property, called Maine elective property, regardless of where it's located or what type of property it is.
A local probate attorney can review your estate — many offer a free consultation.
A Maine QTIP election can't include anything that's already includible as a taxable gift on the federal return, and the maximum figure changes every year along with both exclusion amounts — have a Maine attorney confirm the current-year limit before relying on it.