It is obviously a good sign....but it's no guarantee. I've heard of ppl interviewing more than once at a school and not getting in. On the other hand I have heard of reapplicants getting accepted without a second interview. IDK how UMD does it. This is my first cycle applying and I applied pretty late (Oct.) and have had 6 interviews. Resulting in 4 waitlists and I hear back from the other 2 schools this week hopefully. There are def issues with my application and areas where I could/need to improve
If you applied late this cycle then you are probably competitive but the class got filled. If you applied early but just got an interview late then you probably need to work on your application/stats if you don't get in this cycle.
Also, if you applied to many schools and just got one interview then you probably should work on your application (if you end up needing to reapply).