Plasterers' Local Union No. 31 is currently affiliated with many organizations including:
- AFL - CIO
- Pennsylvania Building & Construction Trades Council
- North Central Pennsylvania Building & Construction Trades Council
- Great Lakes Building & Construction Trades Council
- Southwestern Pennsylvania Building & Construction Trades Council
- Pittsburgh Building & Construction Trades Council
- Beaver County Building & Construction Trades Council
- Altoona Building & Construction Trades Council
- Butler & Venango Counties Building & Construction Trades Council
- Johnstown Building & Construction Trades Council
- Lawrence County Building & Construction Trades Council
- Mercer County Building & Construction Trades Council
- Central Labor Union & Industrial Union Council
- Builders Guild
- Pennsylvania Apprentice Coordinators Association
- O.P & C.M.I.A. Tri - State Conference
- O.P & C.M.I.A. North East Conference
- O.P & C.M.I.A. Ohio State Conference
- International Foundation for Employee Benefit Plans
- Foundation for Fair Contracting
- Ohio State Building & Construction Trades Council
- Cleveland Building & Construction Trades Council
- North Central Ohio Building & Construction Trades Council
- Ohio State AFL-CIO