May 29 (Reuters) - Massachusetts sued a UnitedHealth insurance unit on Friday, ‌accusing it of defrauding the ‌state's Medicaid program out of more than $100 ​million by making older patients appear more seriously ill than they actually were.

Andrea Joy Campbell, the Massachusetts ‌attorney general, ⁠said UnitedHealthcare Insurance, which operates as UnitedHealthcare Community Plans of ⁠Massachusetts, falsely manipulated the health status of MassHealth members enrolled in ​its Senior ​Care Options ​plan to secure ‌higher payments.

UnitedHealth, in a statement, called the complaint "meritless."

Campbell accused UnitedHealth of submitting inaccurate diagnoses for patients 65 and older between 2015 and 2025, ‌to receive higher ​payments from MassHealth and ​advance ​the company's "growth-at-all-costs strategy."

The lawsuit accuses ‌UnitedHealth of submitting false ​claims ​and unjust enrichment. It seeks to recoup money that MassHealth improperly ​paid, and ‌seeks triple damages.

(Reporting by Jonathan ​Stempel in New York: Editing ​by Chiara Rodriquez)