Welcome to Flyertalk BWI Blues!
I used to live in Odenton, Baltimore and Greenbelt... so great to see another Marylander!
Most airlines will offer a one-time complementary matching of status from a competing airline. You just have to usually send them your current statement that indicates your status to them with a request for matching status.
However, you want to make sure that you will be flying them in the following year or you used up your one-time request for nothing.
Also, most airlines, as people here have indicated will not normally comp to their top tier... ie United 1K. Of course, if you can commit to bringing in many thousands of dollars, I am sure an exception can, and will, be made...
William