A $13.2 Million Tax Fight Over Where a Billionaire Really Lived

When Jack Anderson died in 2015 at age 90, Connecticut sent his estate a $13.2 million tax bill, claiming the HMO pioneer and hospital-management executive was domiciled in the state — not in his 9,700-square-foot oceanfront mansion in Vero Beach, Florida, where he had a custom astronomy observatory and where his family gathered every Christmas. The ensuing legal battle has now stretched more than a decade, becoming one of the most prominent examples of the intensifying war between states and wealthy Americans over residency.

Anderson's $108 million estate is complex: he owned three condominiums in Greenwich totaling 9,000 square feet, a mountaintop home in Arizona, and the Vero Beach oceanfront property, with luxury cars — including Jaguars, Bentleys, and Lexuses — registered at each location. The estate argued he was clearly a Florida resident: his autobiography consistently referred to Texas and then Florida as home, his will listed the Vero Beach address, and he held a Florida driver's license, gun registration, and voter registration. He had formally declared Florida as his domicile.

The trial court was unpersuaded, zeroing in on one damning detail: Anderson spent roughly 5.5 months per year in Greenwich (May through mid-October) versus just 3.5 months in Florida. The judge ruled that where Anderson spent the most time — his "most valuable and limited resource" — was the most persuasive indicator of domicile, dismissing formalities like the Florida driver's license as mere administrative one-time tasks. The court found the Connecticut and Florida connections roughly equal but said the estate failed to meet the demanding "clear and convincing evidence" standard to rebut Connecticut's presumption that he was a Connecticut domiciliary.

In a pivotal June 2026 ruling, the Connecticut Supreme Court lowered that evidentiary bar, holding that the estate only needs to prove by a "preponderance of the evidence" — a meaningfully easier standard — that Connecticut was not Anderson's true home. The case now goes back to a lower court for an essentially fresh trial. Lawyers caution it's still no guaranteed win: the state's time-spent argument remains powerful.

The case lands amid a broader crackdown on wealthy Americans' residency claims. States are conducting more residency audits, New York City recently enacted a pied-à-terre tax on nonresidents, and California has proposed a billionaire wealth tax. Connecticut's estate and gift taxes generated an estimated $261 million in the last fiscal year alone. The Anderson estate's decade-long fight — four-day trial, 10 witnesses, 200 exhibits, and 4,000 pages of tax returns — illustrates just how high the stakes are and how murky the rules remain for the ultra-wealthy who split time across multiple states.