UB04 Type of Bill Code 0851: Specialty Facility - Critical Access Hospital

Overview

The code structure, as defined by Noridian, consists of a leading zero (ignored by CMS), followed by the second digit "8" indicating a special facility or hospital (CAH, ASC surgery), the third digit "5" representing Intermediate Care - Level I for special facilities, and the fourth digit "1" signifying an Admit Through Discharge frequency ^[1]. This code is specifically designed for Critical Access Hospitals, which are small, rural facilities designated by Medicare to provide essential healthcare services to underserved communities. The "0851" code indicates that the claim covers the entire inpatient stay from admission through discharge, without interim billing. Understanding this code is crucial for accurate billing and reimbursement, as it directly impacts how Medicare and other payers process claims for CAH services.

When to Use

This code applies specifically when the facility type is a special facility or hospital (digit 8), the type of care is Intermediate Care - Level I (digit 5), and the frequency is a single claim covering the entire stay (digit 1) ^[1]. The code should not be used for other facility types such as acute care hospitals (digit 1), skilled nursing facilities (digit 2), or clinics (digit 7). Additionally, it is not for outpatient services, which would use a different third digit (e.g., 3 for outpatient). When submitting claims to MassHealth, providers must ensure they have an approved electronic claim submission waiver to submit paper UB-04 forms, as MassHealth adopted an all-electronic claims submission policy effective January 1, 2012 ^[2]. Use this code only for CAH inpatient stays where the patient is admitted and discharged within the same billing period.

Step-by-Step Claim Example

Scenario: A Critical Access Hospital in rural Massachusetts admits a patient for a three-day inpatient stay for pneumonia treatment. The patient is admitted on March 1, 2025, and discharged on March 3, 2025. The hospital submits a single claim for the entire stay using Type of Bill 0851.

Step 1: Complete the UB-04 Form Header

• Enter the provider's National Provider Identifier (NPI) and Medicare ID in the appropriate fields.
• Use the hospital's name, address, and contact information as the billing provider.

Step 2: Enter Type of Bill Code

Step 3: Complete Patient Information

• In Field 8a, enter the patient's Health Insurance Claim Number (HICN) or Medicare Beneficiary Identifier (MBI).
• In Fields 9a through 9c, enter the patient's name, address, and date of birth.

Step 4: Enter Admission and Discharge Dates

• In Field 12, enter the admission date: 03/01/2025.
• In Field 13, enter the discharge date: 03/03/2025.

Step 5: Enter Diagnosis Codes

• In Field 67, enter the principal diagnosis code (e.g., J15.9 for unspecified bacterial pneumonia).
• In Fields 67A through 67Q, enter any secondary diagnosis codes.

Step 6: Enter Procedure Codes

• In Field 74, enter the principal procedure code (e.g., 0BJ00ZZ for bronchoscopy).
• In Field 74A, enter the procedure date: 03/02/2025.

Step 7: Enter Revenue Codes and Charges

• In Field 42, list revenue codes for each service (e.g., 0120 for room and board, 0250 for pharmacy, 0300 for laboratory).
• In Field 43, enter the corresponding revenue descriptions.
• In Field 44, enter the HCPCS/CPT codes if applicable.
• In Field 47, enter the total charges for each revenue code.

Step 8: Calculate and Enter Total Charges

• In Field 48, enter the total charges for all services (e.g., $15,000).

Step 9: Submit the Claim

• Since MassHealth requires electronic submission unless a waiver is approved, ensure the provider has an approved waiver before submitting the paper UB-04 form ^[2]. If submitting electronically, use the equivalent electronic format (e.g., 837I) with the same Type of Bill code.

Common Mistakes & Audit Red Flags

1. Incorrect Facility Type Digit: Using a facility type other than "8" (special facility) for a Critical Access Hospital. For example, using "1" (hospital) instead of "8" can lead to claim rejection or incorrect payment. Always verify that the second digit matches the CAH designation ^[1].

2. Wrong Type of Care Digit: Using "1" (inpatient Part A) instead of "5" (Intermediate Care - Level I) for CAH inpatient services. The third digit must be "5" for CAH inpatient care, not "1" which is for acute care hospitals. This mismatch can cause the claim to be processed under the wrong payment methodology.

3. Incorrect Frequency Digit: Using a frequency digit other than "1" for a single claim covering the entire stay. For example, using "2" (interim first claim) when the patient is discharged within the billing period. This can result in duplicate claims or payment delays.

4. Missing or Incorrect Dates: Failing to enter accurate admission and discharge dates in Fields 12 and 13. Inconsistent dates can trigger audits for potential fraud or billing errors.

5. Revenue Code Mismatches: Using revenue codes that are not appropriate for CAH inpatient services. For example, using revenue code 0450 (Emergency Room) for an inpatient stay without proper documentation. Ensure revenue codes align with the services provided.

6. Failure to Obtain Waiver: Submitting a paper UB-04 claim without an approved electronic claim submission waiver from MassHealth. As of January 1, 2012, MassHealth requires all claims to be submitted electronically unless a waiver is granted ^[2]. Submitting without a waiver will result in claim rejection.

7. Duplicate Billing: Submitting both a paper UB-04 and an electronic claim for the same service. This can lead to duplicate payments and subsequent recoupment actions.

8. Incomplete Diagnosis Coding: Failing to include all relevant diagnosis codes or using unspecified codes when specific codes are available. This can lead to medical necessity denials or audits.

Related Codes/Fields

Code/Field	Description	Relationship to 0851
0850	Specialty Facility - CAH (Non-payment/Zero Claim)	Same facility and care type but with frequency "0" for zero payment claims [1]
0852	Specialty Facility - CAH (Interim - First Claim)	Same facility and care type but with frequency "2" for interim first claims
0853	Specialty Facility - CAH (Interim - Continuing Claims)	Same facility and care type but with frequency "3" for continuing interim claims
0854	Specialty Facility - CAH (Interim - Last Claim)	Same facility and care type but with frequency "4" for final interim claims
0855	Specialty Facility - CAH (Late Charge Only)	Same facility and care type but with frequency "5" for late charges
0857	Specialty Facility - CAH (Replacement of Prior Claim)	Same facility and care type but with frequency "7" for claim replacements
0858	Specialty Facility - CAH (Void/Cancel of Prior Claim)	Same facility and care type but with frequency "8" for voiding claims
0111	Hospital Inpatient (Admit Through Discharge)	Different facility type (1 for hospital) but same frequency; used for acute care hospitals
085X	All CAH Type of Bill Codes	The "X" represents any frequency digit; all codes with facility digit 8 and care digit 5 are CAH-related
Field 12	Patient Admission Date	Required field for all inpatient claims including 0851
Field 13	Patient Discharge Date	Required field for all inpatient claims including 0851
Field 42	Revenue Codes	Must align with CAH inpatient services when using 0851
Field 67	Diagnosis Codes	Required for medical necessity validation with 0851 claims

---END---

---

References

[1] Noridian Bill Types — https://med.noridianmedicare.com/web/jea/topics/claim-submission/bill-types

[2] MassHealth UB-04 Guide — https://www.mass.gov/doc/ub-04-billing-guide-0/download