Property values increased this year on Martha’s Vineyard, topping $20 billion in total assessed value, according to figures from the six towns and the Massachusetts Department of Revenue.

Tax collectors on Martha’s Vineyard are busier than usual as taxpayers rush to prepay property taxes before the end of the year. The reason is the new federal tax regulations.

Against a backdrop of rocketing demand for vacation rentals on the Cape and Islands, state lawmakers are anticipating the passage of a sweeping tax on short-term rentals.

Property tax bills went out, and while homeowners continue to pay less than those on the mainland, their tax burden will be heavier.

In Massachusetts, land used by a charitable organization qualifies for a tax exemption under state law. But a recent case in the town of Hawley, now going before the Massachusetts Supreme Judicial Court, could have wide implications.