www.cms.hhs.gov/home/medicare.asp
Centers for Medicare and Medicaid Services. Your government link for everything Medicare.

www.medicarenhic.com
NHIC, Corp., an ISO 9001:2000 Certified Quality Management System is the Medicare Part B contractor for Maine, Massachusetts, New Hampshire, and Vermont, serving 1.3 million beneficiaries and 52,000 healthcare providers.
NHIC also provides its services to 7.7 million Medicare beneficiaries and 24,000 suppliers of Durable Medical Equipment, Prosthetics, Orthotics and Supplies (DMEPOS) in DME MAC Jurisdiction A which includes Connecticut, Delaware, District of Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont.

http://www.adminastar.com/Providers/DMERC/DMERC.html
AdminaStar Federal’s most significant area of business is the administration of government contracts for Medicare under the authority of CMS. AdminaStar Federal currently administers a Part A contract for the states of Illinois, Indiana, Kentucky, Ohio, as well as holds a Part B contract for the states of Indiana and Kentucky.

www.cignagovernmentservices.com
CIGNA Government Services currently provides Medicare claims processing and support services for Medicare Part B and the states of Tennessee, North Carolina, and Idaho. On June 1, 2007, CIGNA assumed full operations for DME MAC Jurisdiction C (formerly DMERC Region C) for the states of: Alabama, Arkansas, Colorado, Florida, Georgia, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, U.S. Virgin Islands, Virginia, and West Virginia.

www.noridianmedicare.com
Noridian Administrative Services is the contractor for Jurisdiction D. Jurisdiction D includes Alaska, American Samoa, Arizona, California, Guam, Hawaii, Idaho, Iowa, Kansas, N. Mariana Islands, Missouri, Montana, Nebraska, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming.

www.ngsmedicare.com
National Government Services administers the Medicare Part A (hospital insurance) contract for the states of Connecticut, Delaware, Illinois, Indiana, Kentucky, Maine, Massachusetts, Michigan, New Hampshire, New York, Ohio, Vermont, Virginia, West Virginia, Wisconsin, and the U.S. Territories of American Samoa, Guam, and Northern Mariana Islands.
National Government Services administers the Medicare home health & hospice contract for the states of Alaska, Arizona, California, Connecticut, Hawaii, Idaho, Maine, Massachusetts, Michigan, Minnesota, Nevada, New Hampshire, New Jersey, New York, Oregon, Rhode Island, Vermont, Washington, and the U.S. Territories of American Samoa, Guam, Northern Mariana Islands, Puerto Rico, and U.S. Virgin Islands.
National Government Services is the Jurisdiction B Durable Medical Equipment Medicare Administrative Contractor for the states of Illinois, Indiana, Kentucky, Michigan, Minnesota, Ohio, and Wisconsin.