Technical Advice Memorandum (T.A.M., Tech. Adv. Mem., T.A. Memo)Written advice provided by the national IRS to local offices by request of an IRS district director or an IRS area director. A TAM responds to a technical or procedural question that arises during the examination of a taxpayer’s return. Similar to letter rulings, but relate to completed taxpayer transactions and rely on previously established authority, e.g. revenue rulings, regulations.