The code prohibits companies from hiring municipal employees or their relatives and from providing compensation for municipal approval. It bars companies from giving gifts of more than $10 during a one-year period.
While the code will govern future activity, investigations are ongoing into allegations that developers bribed local officials to push through wind power projects.
Cuomo said New York must be equally devoted to clean energy and clean government.
"If we have a complaint from the past, we investigate a complaint," he said. "The code clarifies the rules going forward."
Deputy Attorney General Robin Baker said penalties range up to $50,000 for the first violation and up to $100,000 for subsequent violations. In all, 16 companies have signed the code, representing about 90 percent of the growing industry in New York.
Reunion Power signed the code after initially refusing and then receiving a subpoena.
According to the attorney general's office, 16 wind farms operate in New York and 54 projects or expansions are in the proposal stage.
Paul Copleman, spokesman for Iberdrola Renewables, a co-owner of the 321-megawatt Maple Ridge wind farm with 195 towers on the Tug Hill Plateau in northern New York, said the code "largely reinforces practices we've been engaged in as a developer."