So long as the information that is required to be in the SPD is included, a single document can be used as the Plan Document and SPD for simple welfare plans. Also there must be some verification that the company formally adopted the plan, this is usually achieved with a signature page signed by an Office of the company.
Since welfare plans are typically less technical than pension plans, the Plan document and SPD can be combined into a single document which the employer can use for both purposes.
