The subpoena was served late Monday on the company, Aon, one of the largest insurance brokerage firms in the world, as part of an inquiry by the New York State Department of Financial Services.
It came just days after Michael D. Cohen, Mr. Trump’s former fixer and lawyer, indicated in congressional testimony that the Trump Organization inflated the value of its assets to insurance companies.
The subpoena is the latest sign that the Trump Organization is facing scrutiny from multiple fronts — federal prosecutors, congressional Democrats, and now, insurance regulators.
The Department of Financial Services does not conduct criminal investigations, nor does it have authority over Mr. Trump or the Trump Organization, but it can refer any possible illegal activity to prosecutors.
The federal prosecutors in Manhattan have been investigating the Trump Organization’s role in hush money payments to women who claimed to have affairs with Mr. Trump. Mr. Cohen, who pleaded guilty to federal crimes in connection with those payments, has also told the prosecutors about irregularities in the company’s insurance practices, The New York Times reported last month.
While the prosecutors are largely viewed as independent, the president and his allies have dismissed much of the other scrutiny as politically motivated.
The subpoena from the state agency that regulates insurance, which is part of the administration of Gov. Andrew M. Cuomo, a Democrat and vocal critic of Mr. Trump, landed on the same day that even broader scrutiny came to bear on the president, his administration and his business from House Democrats.
The House Judiciary Committee on Monday unleashed a blizzard of 81 letters demanding documents from people and businesses, including President Trump’s company and several of his family members, kicking off the committee’s sweeping investigation into possible obstruction of justice, corruption and abuse of power by Mr. Trump.
The subpoena that was served on Aon contains no indication that the company or any of its employees engaged in misconduct, the person said. Nor does it specify any possible wrongdoing that is the focus of the inquiry by state regulators.
Insurance brokers such as Aon help companies evaluate their risk and connect them with underwriters, the companies that offer the actual coverage. For this service, the brokers receive a fee or commission, usually paid by the client.
The nine-page subpoena demands a broad range of materials regarding Aon’s business with Mr. Trump and the Trump Organization dating back to 2009, according to the person briefed on the matter, who spoke on the condition of anonymity because he was not authorized to discuss it publicly.
Among other things, it seeks copies of all communications between Aon and Mr. Trump and the Trump Organization, as well as all internal Aon documents relating to Mr. Trump and the company, the person said.
The regulators are also looking at compensation for the current and former Aon employees who handled the Trump Organization account, seeking information about their incentives, bonus payments or commissions. They are seeking similar contracts and agreements between Aon and Mr. Trump.
A spokeswoman for Aon, Donna Mirandola, said the company intended to cooperate, adding: “We do not comment on specific client matters.” The White House referred a request for comment to the Trump Organization, which did not respond to requests for comment. A spokesman for the Department of Financial Services declined to comment.
The Department of Financial Services is a powerful agency that regulates and supervises the insurance industry — including brokers, brokerage firms and underwriters in New York — as well as banking and other financial institutions.
The agency’s authority is limited to civil regulatory actions, although it can refer possible criminal conduct to the office of a local district attorney or the State Attorney General.
However, under the New York State insurance law, the department, headed by Acting Superintendent Linda A. Lacewell, can take action against the companies and individuals it regulates, including brokers and underwriters. It can issue fines or a range of other penalties, including revoking their licenses to do business in New York.
This is not the first time that the agency has examined the business practices involving the Trump Organization. In 2017, the agency scrutinized the company’s long relationship with Deutsche Bank, which the agency regulates and which is one of the president’s few lenders on Wall Street. The examination concluded without the agency taking any action against the bank.
Mr. Cohen’s testimony, however, provides additional fuel to advance the insurance inquiry.
At a hearing in front of the House Oversight Committee last week, when asked by Rep. Alexandria Ocasio-Cortez, a New York Democrat, whether the president ever inflated his assets to an insurance company, Mr. Cohen simply replied, “Yes.”
The New York regulators are requesting copies of the insurance policies ultimately issued to Mr. Trump and the Trump Organization, as well as applications and financial statements used to secure the policies, the person said.
The subpoena requests that the materials — undoubtedly a vast swath of documents, data, emails, policies and other records — be turned over by March 19. The regulators will likely then issue additional subpoenas or requests to the underwriters and possibly other companies and individuals identified in response to this subpoena.
It could take the agency’s investigators months to analyze all the information they collect.