Some residents in America’s richest zip code have alleged the master association is disproportionately dipping into their wealth for dues, while letting others slide with paying less than they owe.

Fisher Island, a Biscayne Bay barrier island near Miami Beach and PortMiami, is said to have the highest income per capital. It’s also home to the likes of supermodel Karolina Kurkova and TV producer Barney Rosenzweig, though they aren’t among the plaintiffs.

A putative class action by the owners of more than 15 units against Fisher Island Community Association Inc. said the master association has burdened most owners with a higher share of assessments and expenses, overcharging them by more than $11 million over the past five years.

That number could be higher, as the Miami-Dade Circuit Court complaint filed on Friday said the exact amount is to be determined at jury trial.

The Fisher Island Community Association and its attorneys at PeytonBolin Law in Fort Lauderdale didn’t immediately provide comment. The defendant is the master association above 22 condominium associations and homeowners association on the island.

The suit says the Fisher Island Community Association levies general and special assessments as well as capital improvement expenses for common areas — but takes issue with how the association divvies up the dues among property owners.

The association has allegedly allowed some residents to combine their units or lots into one property, thereby allowing them to pay one assessment for both properties. This is illegal under association governing documents that say an assessment and other expenses should be levied per lot and per unit, according to the complaint. The suit also alleges violations of state law.

The net effect is to divvy the total assessments and expenses against fewer properties, disproportionately burdening owners of uncombined lots and units with costs.

“By combining units and only charging one FICA assessment, FICA unlawfully requires owners of uncombined units to subsidize the cost of living on Fisher Island for the owners of combined units,” filing attorney Joshua Alper said in the complaint.

Alper filed with Arletys Hernandez, both of of Morgan & Morgan.

To illustrate the issue, the complaint includes a breakdown of the association’s annual budgets and assessments since 2016.

Last year, the budget was $24.15 million and dues should have been spread across all 892 properties, meaning each owner pays $27,075. But because 50 units were combined, the dues were spread across only 842 properties, meaning each owner paid $28,683, according to the complaint.

This means that the 50 combined lots or units didn’t pay anything, while the remaining owners of uncombined lots or units were overburdened by $1,608, the complaint said.

The complaint also said that because the master association illegally allows for the combination of lots or units, the number of properties is in constant flux. This year there are 52 combined units, while there were 48 combined units in 2016.

The complaint lists declaratory judgment, breach of contract and injunctive relief counts.

Alper added that all this amounts to the association ultimately taking advantage of residents.

“Its alleged misconduct,” he said, “has forced the majority of the owners to pay millions of dollars in improper fees each year over, at least the last five years.”