The Obama administration said Wednesday that it had granted broad waivers to four states allowing health insurance companies to continue offering less generous benefits than they would otherwise be required to provide this year under the new federal healthcare law. The states are Florida, New Jersey, Ohio and Tennessee, the administration told Congress. Lawmakers said that many other states, insurers and employers needed similar exemptions from some of the law's requirements and would seek waivers if they knew of the option. Steven B. Larsen, a top federal insurance regulator, said the waivers would allow many consumers to keep the coverage they had, a goal often espoused by President Obama. Under the law and rules issued by the administration, health plans this year must generally provide at least $750,000 in coverage for essential benefits like hospital care, doctors' services and prescription drugs. In states granted the waivers, many health plans with much lower annual limits on coverage may continue to operate.