A package for a medical device such as an intermittent catheter has a case and a cap connected by threads. The case includes a hollow tube which is closed at one end and open at the other. A shoulder is formed near one end of the case. Above the shoulder is a cylindrical ferrule that includes external threads. The cap has internal threads selectably engageable with the threads on the ferrule to form a liquid-tight seal between the cap and case when the cap is installed on the case.