Every successful classifier relies on a strong foundation of trusted OPM resources. These references provide the structure, definitions, and guidance that ensure consistency and fairness across the federal classification process. For new HR professionals, learning how to navigate and apply these documents is the first step toward mastering the art and science of position classification.
Mastering these four core references gives HR professionals the tools to classify positions accurately, defend their decisions, and uphold the merit principles that define federal service. By becoming comfortable with OPM’s official resources, classifiers not only improve the quality of their work but also contribute to a fair and transparent system that supports every agency’s mission.
As a federal HR professional or new classifier, it’s important to know where to find reliable guidance when you need it. There are four key references that every classifier should understand. You don’t need to memorize them, but you should know how to use each one to locate essential information and support your decisions. The following overview introduces these core resources and explains why they are so important in your daily work.
The Introduction to the Position Classification Standards is a foundational guide developed by the U.S. Office of Personnel Management (OPM) for both managers and classifiers. It explains the authorities, definitions, and principles that form the basis of the federal classification process. This is the best place for new classifiers to begin, as it offers clear direction on topics such as determining major duties, using standards, and understanding classification policies.
Key sections to review include the Table of Contents, Section II on the Structure and Use of Classification Standards (including the Explanation of Terms), and Section III on the Principles and Policies of Position Classification. Section III is particularly useful for understanding authorities and responsibilities for classification, work covered by the General Schedule, how to use position descriptions, and how to determine which duties should be classified.
The Classifier’s Handbook is often considered the most frequently used reference for classifiers. It builds upon the material in the Introduction and goes into greater technical depth, covering topics such as job factors, evaluation methods, and guidance for applying OPM standards. Most classifiers will rely on this handbook regularly as part of their everyday work.
The Handbook of Occupational Groups and Families outlines every General Schedule (GS) occupational group and series in Part I and every Federal Wage System (FWS) job family and series in Part II. It defines each occupational series and notes which ones have specific classification standards. This resource is essential when determining the correct occupational code and ensuring that the right standards are applied to a position.
The Digest of Significant Classification Decisions and Opinions compiles excerpts from OPM decisions and opinions issued through classification appeals. These cases can serve as useful precedents and help classifiers interpret how specific classification principles have been applied in real-world situations.
Together, these four OPM references provide the essential foundation for any classifier. Whether you are developing a position description, evaluating job duties, or resolving complex classification issues, knowing where to look and how to apply these resources ensures accuracy, consistency, and confidence in your work.