A managed care company is buying more support services from a longtime vendor.

Tufts Health Plan, Watertown, Mass., will be buying payment management services from Emdeon Corp., Nashville, Tenn.

Tufts has been buying electronic data interchange services and related services from Emdeon for about 10 years.

Emdeon now will help Tufts with tasks such as transmission of electronic explanations of benefits to health plan members and electronic payments to providers and vendors, Emdeon says.