Swing Bed Coding in ICD-10-CM: Key Guidelines for Coders

This blog explores swing bed coding in ICD-10-CM, including how to assign principal diagnoses, apply aftercare Z codes vs. injury codes, and follow official guidelines. Learn common challenges coders face in swing bed settings and discover resources to strengthen your coding accuracy, including our Swing Bed Coding in ICD-10-CM eBook.

Swing bed facilities play a unique role in healthcare delivery—especially in small or rural hospitals where flexibility is vital. For coders, swing bed assignments bring a set of challenges that differ from both acute care and skilled nursing facility (SNF) settings, making it essential to understand the nuances of proper code selection and documentation requirements.

What is a Swing Bed?

The Centers for Medicare and Medicaid Services (CMS) permits certain hospitals—typically critical access hospitals (CAHs) or small rural hospitals—to enter into a swing bed agreement. This agreement allows hospitals to use beds interchangeably for acute inpatient care or SNF-level care, depending on patient need.

Medicare Part A covers post-hospital extended care services furnished in swing beds, and while CAHs are exempt from the SNF prospective payment system (PPS), PPS rules do apply to most swing bed facilities. To qualify, patients must have completed a medically necessary inpatient stay of at least three consecutive days.

Coding Considerations for Swing Bed Patients

Swing bed patients are coded using the same ICD-10-CM Official Guidelines for Coding and Reporting that apply to long-term care facilities. While many coding rules overlap with acute care, swing bed encounters require special attention to the principal diagnosis (PDX) and the reason for admission to swing bed status.

Determining the Principal Diagnosis

The most frequent challenge is selecting the correct PDX. For swing bed patients, the principal diagnosis is defined by the condition chiefly responsible for the swing bed admission—not necessarily the condition treated during the acute care stay.

For example:

• A patient recovering from a joint replacement may have Z47.1, Aftercare following joint replacement surgery as the PDX.
• A patient admitted for ongoing antibiotic therapy for osteomyelitis would have acute osteomyelitis coded as the PDX.
• A stroke patient with residual hemiparesis would be coded using an I69 residual condition code, not the acute CVA.

When to Use Z Codes vs. Injury Codes

• Aftercare Z Codes apply when treatment has been completed, but the patient requires continued recovery support (e.g., post-surgical aftercare).
• Injury Codes with 7th characters are used instead of Z codes for trauma cases, such as fractures during healing. For example, a patient in swing bed status for fracture aftercare would be coded with the injury code and appropriate 7th character for subsequent encounter.

Why Swing Bed Coding Matters

Accurate swing bed coding ensures compliance, proper data reporting, and correct reimbursement. It also affects patient outcomes tracking and quality metrics—making coder expertise crucial.

However, coders often face challenges such as:

• Distinguishing between resolved acute conditions vs. ongoing aftercare needs
• Knowing when to assign aftercare Z codes vs. injury codes
• Applying UHDDS definitions of principal and secondary diagnoses in non-acute settings

Getting it wrong can lead to compliance issues and inaccurate data reporting, which is why specialized training and reliable resources are invaluable.

Go Deeper with Our Swing Bed Coding eBook

Our comprehensive eBook, Swing Bed Coding in ICD-10-CM, provides step-by-step guidance, real-world examples, and clear explanations of documentation and coding rules. You’ll learn how to:

• Correctly assign principal and secondary diagnoses for swing bed encounters
• Differentiate when to use Z codes vs. injury codes
• Apply coding guidelines to residual conditions, aftercare, and acute continuation of care
• Avoid common compliance pitfalls in swing bed coding

Purchase the eBook here and strengthen your swing bed coding accuracy with confidence.

For more than 30 years, HIA has been the leading provider of compliance audits, coding support services and clinical documentation audit services for hospitals, ambulatory surgery centers, physician groups and other healthcare entities. HIA offers PRN support as well as total outsource support.

The information contained in this coding advice is valid at the time of posting. Viewers are encouraged to research subsequent official guidance in the areas associated with the topic as they can change rapidly.