UB04 Field 4: Type of Bill

Introduction

Field 4 (Type of Bill) is a critical four-digit code used on the UB-04 claim form to identify the specific type of facility, the classification of care, and the frequency of the claim. Often referred to as Box 4, this field is essential for payers to determine how to process and reimburse the medical claim based on the setting and duration of services.

Requirements

Requirement	Status
Inpatient Requirement	Required
Outpatient Requirement	Required
Format	4-character numeric code
Source	National Uniform Billing Committee (NUBC)

Billing Tips

When completing Box 4, ensure the first digit is always a leading zero (though some systems may truncate it, the NUBC standard identifies it as a four-digit field). The second digit indicates the type of facility, the third digit defines the bill classification, and the fourth digit represents the frequency of the bill (e.g., original, replacement, or void). Incorrect coding in Field 4 is a leading cause of immediate claim rejections.

Code Reference

• 0111 - Hospital Inpatient (Including Medicare Part A) - Admit through Discharge Claim
• 0112 - Hospital Inpatient (Including Medicare Part A) - Interim - First Claim
• 0113 - Hospital Inpatient (Including Medicare Part A) - Interim - Continuing Claim
• 0114 - Hospital Inpatient (Including Medicare Part A) - Interim - Last Claim
• 0117 - Hospital Inpatient (Including Medicare Part A) - Replacement of Prior Claim
• 0118 - Hospital Inpatient (Including Medicare Part A) - Void/Cancel of Prior Claim
• 0121 - Hospital Inpatient (Medicare Part B only) - Admit through Discharge Claim
• 0131 - Hospital Outpatient - Admit through Discharge Claim
• 0132 - Hospital Outpatient - Interim - First Claim
• 0133 - Hospital Outpatient - Interim - Continuing Claim
• 0134 - Hospital Outpatient - Interim - Last Claim
• 0137 - Hospital Outpatient - Replacement of Prior Claim
• 0141 - Hospital Other (Part B) - Admit through Discharge Claim
• 0181 - Hospital Swing Bed - Admit through Discharge Claim
• 0211 - Skilled Nursing - Inpatient (Medicare Part A) - Admit through Discharge Claim
• 0221 - Skilled Nursing - Inpatient (Medicare Part B only) - Admit through Discharge Claim
• 0231 - Skilled Nursing - Outpatient - Admit through Discharge Claim
• 0321 - Home Health - Inpatient (Plan of Care) - Admit through Discharge Claim
• 0322 - Home Health - Interim - First Claim
• 0341 - Home Health - Outpatient (Other) - Admit through Discharge Claim
• 0721 - Clinic - ESRD - Admit through Discharge Claim
• 0751 - Clinic - Comprehensive Outpatient Rehabilitation Facility (CORF)
• 0811 - Specialty Facility - Hospice (Non-Hospital Based) - Admit through Discharge Claim
• 0821 - Specialty Facility - Hospice (Hospital Based) - Admit through Discharge Claim
• 0831 - Specialty Facility - Ambulatory Surgery Center
• 0851 - Specialty Facility - Critical Access Hospital