The False Health Care Claims Act (M.G.L. Chapter 175H) covers false claims and misrepresentations in health care coverage or benefit claims.
The Massachusetts Medicaid False Claims laws.
Federal laws including the False Claims Act, anti-kickback statutes, and laws against false statements to government health care programs.

Civil penalties: repayment of false or overbilled amounts, possibly multiplied, plus attorney’s fees and investigation costs.
Criminal penalties: fines and imprisonment depending on severity and whether federal or state charges.
Additional sanctions could include exclusion from government health programs, loss of professional license, reputational harm.

State investigations are conducted by the Massachusetts Attorney General’s Medicaid Fraud Division and other state regulatory or licensing boards.
Federal investigations may involve the U.S. Department of Health & Human Services Office of Inspector General, DOJ, Medicare/Medicaid auditors, etc.
Investigations often include audits of billing records, examination of medical necessity, reviews of provider referrals, kickbacks or inducements, document subpoenas.

Retain experienced legal counsel right away.
Preserve all relevant records and documentation (claims data, medical charts, communications).
Evaluate whether there were any policies, procedures, or compliance programs in place, and whether cooperation or self-reporting might help reduce exposure.
Understand the possible defenses (e.g. lack of intent, error vs knowing fraud, whether services were legitimate or necessary).