Will I get paid for overtime? http://pda.gov.gh/index.php/drugs-price-list-in-pakistan-97f2.pdf#death silk road and the online drugs trade truthloader investigates  Typically, it's best to buy a Medigap policy during your open enrollment period, which runs for six months and starts on the first day of the month in which you are age 65 and enrolled in Medicare Part B. Insurance companies are required under the law to sell you a policy during open enrollment. They can't exclude pre-existing conditions, or charge a higher premium due to any past health problems.