LYNN – State officials are cracking down on healthcare facilities that submit fraudulent bills for insurance reimbursement.The state attorney general’s office in conjunction with the Insurance Fraud Bureau held a summit earlier this month at the Kennedy Library in Boston to address the problem.Physical therapists and chiropractors rank high among providers who submit billing for reimbursement. As a result of enforcement by state investigators, the number of insurance reimbursement requests submitted by businesses providing those services has dipped markedly since 2003.For instance, high-volume physical therapy service providers in Lynn billed for more than $5 million in reimbursement during 2003. That number dropped to slightly over $3 million in 2007.Chiropractic services in Lynn billed for approximately $2.9 million in services in 2003, and less than $1.5 million in 2007.In Lynn, 14 chiropractic services submitted 866 claims and billed for $2.8 million in services in 2003. By 2007, only seven chiropractic services submitted 512 claims for a total $1.4 million.Billing by physical therapy services followed a similar pattern in Lynn. In 2003, seven providers submitted 716 claims for $2.3 million. Last year, four providers submitted 478 claims for $1.8 million.The reduction in the number of claims submitted and, as a result, the total about of billing, was attributed to stepped up scrutiny by state claims investigators.