Washington State

Office of the Attorney General

Attorney General

Bob Ferguson


Dentists billed for services they didn’t provide, charged for more expensive services than they provided

VANCOUVER — Attorney General Bob Ferguson announced today that CareOne Dental Corporation and its owners will pay $1 million over allegations they repeatedly billed Medicaid for non-covered services and for services the company didn’t provide, the second-largest resolution of an in-state Medicaid False Claims Act case in Washington.

One of the defendants, Dr. Liem Do, also agreed to no longer provide or be employed in any setting that involves state Medicaid and Medicare services. He also agreed that if Medicaid and Medicare initiate formal proceedings to bar him, he waives his right to contest them, a process known as “voluntary exclusion.”

In 2015, Ferguson filed a Medicaid fraud lawsuit in Clark County Superior Court against the Clark County company and its owners, Dr. Do and his wife Dr. Phuong-Oanh Tran. Ferguson alleged that CareOne Dental filed about $1 million in fraudulent claims to Medicaid between January 2011 and June 2015.

At one point, the couple operated four dental offices in Southwest Washington and two in Oregon. They currently operate a single clinic in Vancouver.

“Medicaid funds are a precious resource meant for the health care of Washington families in need,” Ferguson said. “When health care providers defraud Medicaid for their own gain, thereby harming Washington families, my office will hold them accountable.”

One of the defendants’ common practices was to bill non-covered services to Medicaid as covered procedures, for example, billing sealants, which are not covered, as restorations or fillings. They also billed for more expensive procedures than those actually provided, a practice known as “upcoding.”

For example, in one instance, CareOne submitted bills for fillings on eight teeth, when the dentist actually performed non-covered sealants.

Former CareOne employees verified these behaviors, and confirmed that Dr. Do would alter billings submitted to Medicaid to reflect more lucrative services than had actually been performed. 

Assistant Attorneys General Matthew Kuehn and Karl Sloan with the Attorney General’s Medicaid Fraud Control Division handled the case for Washington.

The Medicaid Fraud Control Division investigates and prosecutes health care provider fraud committed against the state’s Medicaid program under the Medicaid Fraud False Claims Act. Since 2012, the Medicaid Fraud Control Division of the Attorney General’s Office has obtained recoveries in excess of $146 million for Washington state.

Like all recoveries from the Medicaid Fraud Control Division, the $1 million goes back into Medicaid through the state Medicaid Fraud Penalty Account.

Legislation requested by Ferguson last year expanded the law enforcement powers of Medicaid Fraud Division investigators. For the first time in the division’s history, its investigators can now issue search warrants without the assistance of other law enforcement agencies.


The Office of the Attorney General is the chief legal office for the state of Washington with attorneys and staff in 27 divisions across the state providing legal services to roughly 200 state agencies, boards and commissions. Visit www.atg.wa.gov to learn more.


Brionna Aho, Communications Director, (360) 753-2727; Brionna.aho@atg.wa.gov