A Washington DC mechanics lien is only valid for 180 days after the mechanics lien was filed. If an action to foreclose the claim isn't initiated within that timeframe, the claim will expire and no longer be enforceable. Before deciding to file the lawsuit there is one more step we recommend, sending a Notice of Intent to Foreclose. This is simply a letter stating that if you aren't paid within a certain amount of days, that you will file a foreclosure action. This isn't a required notice in DC, but it is typically effective at inducing payment before having to go to court.
Here are some additional resources:
If you are a current user, open the project, and click the "Create a Doc" tab at the top. You can find the Certified Notice of Intent to Foreclose document under the "Choose Something Else" option. This should automatically import your project information and Levelset will take care of the rest.