UB04 Admission Hour Code 15: 03:00 PM - 03:59 PM

Overview

Admission Hour Code 15 on the UB-04 claim form denotes the one-hour time block of 03:00 PM to 03:59 PM during which a patient was admitted for inpatient care or began outpatient services. This code is part of the admission hour coding system that uses military time (00-23) to specify the precise hour of admission. As defined by CMS, the admission hour code "represents the hour of admission in military time" where Code 00 = 12:00 AM (midnight), Code 01 = 1:00 AM, and continuing through Code 23 = 11:00 PM ^[1].

The admission hour code is entered in Field Locator 13 (FL 13) on the UB-04 form, which is titled "Admission/Start of Care Date." This field is required on inpatient bills only, though it may also be used for outpatient services when applicable. CMS instructs providers to "enter the date the patient was admitted for inpatient care or the date outpatient care began" on FL 13, making the hour code a critical component of the admission timestamp ^[1].

MassHealth requires accurate reporting of admission hour codes to ensure proper claim processing and payment. According to MassHealth billing guidelines, providers must complete all applicable fields on the UB-04 claim form, including time-sensitive data elements like admission hour codes, to avoid claim rejections or processing delays ^[2].

When to Use

Use Admission Hour Code 15 when the patient's actual admission time falls between 3:00 PM and 3:59 PM, inclusive. This applies to both inpatient admissions and outpatient start-of-care scenarios. The code corresponds to military time hour 15, which is 3:00 PM in standard time. According to CMS, "the admission hour code (00-23) represents the hour of admission in military time," meaning Code 15 specifically covers the hour beginning at 15:00 and ending at 15:59 ^[1].

This code should be used in the following situations:

• Inpatient admissions occurring between 3:00 PM and 3:59 PM on the admission date
• Outpatient start of care if the provider's billing system requires hour codes for outpatient services
• Emergency department admissions that convert to inpatient status during this time block
• Scheduled admissions where the patient is physically admitted to the facility during this hour

MassHealth providers must ensure that the admission hour code accurately reflects documented medical record time stamps to maintain compliance. The MassHealth UB-04 billing guide emphasizes that all claim form fields requiring completion should be accurately filled, including time-based codes that affect claim adjudication ^[2].

Step-by-Step Claim Example

Scenario: A patient is admitted to General Hospital on March 15, 2024, at 3:27 PM for an inpatient surgical procedure.

Step 1: Complete Field Locator 12 (Admission Date) with the date of admission: 03/15/2024.

Step 2: In Field Locator 13 (Admission/Start of Care Date), enter the date again: 03/15/2024. Per CMS instructions, "enter the date the patient was admitted for inpatient care" in this field ^[1].

Step 3: Locate the time code section within FL 13 (typically formatted as HHMM or with separate hour/minute fields). Enter the admission hour code: 15.

Step 4: Verify the code selection: 15 corresponds to 3:00 PM - 3:59 PM. Since the admission occurred at 3:27 PM, which falls within this hour block, Code 15 is correct.

Step 5: Complete the remaining UB-04 fields, including patient demographics, insurance information, revenue codes, and diagnosis/procedure codes as required by MassHealth guidelines.

Step 6: Submit the claim electronically or via paper as directed by MassHealth policies. The MassHealth UB-04 guide notes that "effective January 1, 2012, MassHealth adopted an all-electronic claims submission policy," so electronic submission is preferred unless an exemption has been granted ^[2].

Common Mistakes & Audit Red Flags

Mistake 1: Using Code 15 for admissions at 3:00 AM (03:00) instead of 3:00 PM (15:00). Code 15 represents the afternoon hour, not the morning. Admission at 3:00 AM should use Code 03, not 15. This error is common when staff confuse military time with standard time. CMS explicitly states codes range from "00 = 12:00 AM (midnight)" to "23 = 11:00 PM," so providers must differentiate between AM and PM hours ^[1].

Mistake 2: Omitting the admission hour code entirely. Some providers skip the hour code field, thinking it is optional. However, CMS requires this field on inpatient bills, and MassHealth may reject incomplete claims. The MassHealth guide states that "all claims must be submitted electronically" with complete data fields to avoid processing issues ^[2].

Audit Red Flag: Admission hour code inconsistent with documented time in medical records. Auditors may cross-reference the admission hour code with nursing notes, physician orders, or emergency department logs. If a patient's record shows admission at 3:45 PM but Code 16 (4:00 PM) is used, this creates a potential compliance issue. Always verify the exact admission time before assigning the hour code.

Mistake 3: Using Code 15 for an outpatient observation stay or same-day surgery that begins at 3:30 PM when the facility requires separate outpatient start times. Not all facilities use admission hour codes for outpatient services. Check your specific payer's requirements—MassHealth may have different rules for outpatient and inpatient codes ^[2].

Audit Red Flag: Patterns of Code 15 usage near shift changes. If a facility consistently uses Code 15 (3:00 PM) for patients who were actually admitted earlier or later, this may indicate routine rounding errors or deliberate misreporting. CMS and MassHealth both expect accurate time reporting to reflect actual care delivery.

Related Codes/Fields

Field/Code	Description	Relationship to Code 15
FL 12 - Admission Date	Date of admission (MM/DD/YYYY)	Must match the date portion of FL 13 when Code 15 is used
FL 13 - Admission Hour Code 00-23	Military time hour of admission	Code 15 is the specific hour code for 3:00 PM - 3:59 PM
FL 14 - Priority of Admission (Type of Admission)	Code indicating admission type (e.g., emergency, urgent, elective)	Used in conjunction with admission hour to define the admission event
FL 15 - Source of Admission	Code describing where patient came from (e.g., physician referral, transfer)	Complements the admission hour code for complete admission record
FL 16 - Discharge Hour Code (00-23)	Military time hour of discharge	Paired with admission hour to calculate length of stay; no direct relation but both use same coding system
Code 00 (12:00 AM - 12:59 AM)	Midnight hour code	Different time block; used for admissions at or near midnight
Code 16 (4:00 PM - 4:59 PM)	Next hour after Code 15	Used for admissions occurring after 3:59 PM; ensures correct time sequencing

The admission hour code system spans Code 00 through Code 23, with each representing a distinct one-hour block in military time. CMS confirms that "code 00 = 12:00 AM (midnight), 01 = 1:00 AM ... 23 = 11:00 PM" to cover the entire 24-hour day ^[1].

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References

[1] CMS R1915CP — https://www.cms.gov/Regulations-and-Guidance/Guidance/Transmittals/downloads/R1915CP.pdf

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