Domains of the COS-C Exam

by Megan Bernier, MSPT RAC-CT CHS-C COS-C

How to Prepare for the Certificate for OASIS Specialist – Clinical (COS-C) Exam:

Part 4 – Domains of the COS-C Exam

Have you been considering sitting for the COS-C Exam but aren’t sure how to begin preparing or what material would be helpful? This blog series discusses who should consider sitting for the exam, what materials you might find helpful to have at hand when studying and sitting for the exam, some tips for preparing for the exam, and provides a breakdown of the COS-C Exam.

What Does the COS-C Exam Cover?

The COS-C Exam tests you on current CMS guidance related to OASIS regulations, data collection time points, patient populations, data collection conventions, and OASIS item-by-item guidance.

The OASIS guidance concepts covered in the exam are broken into 10 domains with the number of questions from each domain directly proportionate to the actual number of items in the OASIS data set. Broken down into percentages, exam takers can expect to see anywhere between the low and high number of questions in the exam for each domain.

The Domains covered in the exam are:

Domain	% of Exam
Time Points & Regulations	10-15%
Administration & Patient Tracking items	5-10%
Regulations	5-10%
Diagnosis & Sensory Items	10-15%
Bowel & Bladder, Nutrition & Wounds	10-15%
Cognitive & Mood	10-15%
ADLs/IADLs (M1800 – M1870)	10-15%
Functional Activities	10-15%
Medications & Special Treatments	10-15%
ED Use, Inpatient Transfer & Discharge	5-10%

In the final 2 blogs of this series, we will take a brief look at OASIS items and types of questions contained in each domain.

Additional information related to the COS-C Exam can be found on OASIS Answers COS-C Overview webpage. Information specific to the COS-C Exam Domains can be found on the COS-C Exam Preparation webpage.

How to Prepare for the Certificate for OASIS Specialist – Clinical (COS-C) Exam:

Explore the complete six-part series for practical guidance throughout your COS-C Exam preparation. Learn whether the exam is right for you, which materials to use, how to prepare effectively, and what to expect across all 10 exam domains.

Part 1: Why Should You Consider Taking the COS-C Exam
Part 2: What Materials Can I Use to Prepare and Take the COS-C Exam?
Part 3: Tips for Preparing for the Exam
Part 4: What Does the COS-C Exam Cover?
Part 5: The First 5 Domains of the Exam
Part 6: The Last 5 Domains of the Exam