Ann Arbor-based physician network Integrated Healthcare Associates has added UnitedHealthcare to the list of insurance providers it accepts.

UnitedHealth Group’s UnitedHealthcare announced Thursday that it had struck a deal to give its insurance holders access to IHA’s 150 doctors and 30 locations.

The deal comes as IHA is finalizing its merger with St. Joseph Mercy Health System. The relationship between IHA and UnitedHealthcare could accelerate IHA’s expansion. Some 580,000 Michigan residents have UnitedHealthcare insurance.

IHA CEO Bill Fileti told AnnArbor.com in September that IHA would continue to expand its health care delivery network as part of SJHMS, whose parent corporation is nonprofit Catholic health care group Trinity Health.

"Our new network relationship will only improve patients’ access to our physicians," Fileti said in a statement Thursday. "We believe this new relationship will support our patients and expand choice for area residents. We look forward to this new relationship.”

UnitedHealth Group (NYSE: UNH) has $91.9 billion in annual revenue and 80,000 employees. IHA serves 250,000 patients and has close to 1,000 employees.

“UnitedHealthcare and IHA look forward to strengthening our shared commitment to deliver broad access to quality, affordable health care for our customers in the greater Ann Arbor area,” said Jelka Petrovic, CEO of UnitedHealthcare of Michigan, in a statement. “IHA is able to provide a number of important specialty care services and we know our customers will appreciate having new, local access to IHA’s outstanding level of care.”

Contact AnnArbor.com's Nathan Bomey at (734) 623-2587 or nathanbomey@annarbor.com. You can also follow him on Twitter or subscribe to AnnArbor.com's newsletters.