Order a Medco prescription refill by registering on the MedcoHealth.com website, according to Express Scripts. Once a person is registered and logged into the site, he can find any of his prescriptions eligible for renewal listed under the "Prescriptions you can order today" heading.
If no prescriptions are listed under "Prescriptions you can order today," look on the bottom of the page and do a search using the "Find a prescription" feature, explains Express Scripts. A refill can continue an existing prescription, but if the date on a prescription is expired or has no refills left, a prescription renewal must be obtained from a health care professional.
Pharmacy best practices dictate that a refill may be honored at a Medco pharmacy if a surplus amount of medication has not accumulated over the most recent 180 days. Also, at least 75 percent of the medication must have been used, states the North Carolina State Health Plan for Teachers and State Employees. When patients refill monthly medications early, it affects whether their prescriptions are eligible for a refill in the following month. When refill orders are made through the Medco pharmacy, they may be held until the prescription becomes eligible for renewal.