This guide covers how to file and pay your estate tax return; including how to calculate the maximum federal credit. This tax will also apply to the entire estate value.The Massachusetts estate tax ranges from . Explore 2023 state estate tax rates and state inheritance tax rates. In Massachusetts, the estate tax rate is based on a historical federal credit for state death taxes. The deadline to file a Massachusetts state tax return is Tuesday, April 15, 2025. Federal tax returns are also due on Tuesday, April 15.