UB-04 Admission Hour Code 06: 06:00 AM - 06:59 AM

Overview

Code 06 on the UB-04 admission hour field represents the hour from 06:00 AM through 06:59 AM. This code is part of the admission/start of care date field (FL 13) and is required on inpatient bills only. The admission hour must be reported in military time using a two‑digit code from 00 to 23. Code 06 corresponds to 6:00 AM to 6:59 AM. ^[1] The MassHealth UB-04 Billing Guide provides general instructions for completing the UB-04 form and references code sets used on the claim, though it does not list specific admission hour codes. ^[2]

When to Use

Use code 06 when a patient is admitted for inpatient care during the hour between 06:00 AM and 06:59 AM. The admission hour code is mandatory on inpatient bills and must be entered in FL 13 along with the admission date. The code represents the full hour; for example, an admission at 6:15 AM or 6:45 AM both use code 06. ^[1] Outpatient claims do not require an admission hour code; FL 13 is used for the start of care date on outpatient bills, but the hour code is typically omitted or left blank per payer instructions. ^[2] (The guide notes that FL 13 is for admission/start of care date, but does not specify hour code requirements for outpatient; the CMS transmittal explicitly states the hour code is for inpatient bills.)

Step-by-Step Claim Example

Consider a patient admitted to the hospital at 6:30 AM on March 15, 2024. On the UB-04 claim form, the provider completes FL 13 as follows:

• Admission Date: Enter the date of admission (e.g., 03/15/2024) in the date field.
• Admission Hour Code: Enter the two‑digit code 06 in the hour field, indicating the admission occurred between 06:00 AM and 06:59 AM.

(The guide references code sets but does not provide a step‑by‑step example; the CMS transmittal supplies the specific hour code definition.)

Common Mistakes & Audit Red Flags

• Using code 06 for 6:00 PM: The hour 6:00 PM is 18:00 in military time and must be coded as 18, not 06. Using 06 for an evening admission will cause a mismatch with the actual time of admission. ^[1]
• Omitting the hour code entirely: FL 13 requires both the date and the hour code on inpatient bills. Leaving the hour field blank can result in claim rejection or a request for correction.
• Using a single digit instead of two digits: The code must be entered as “06” not “6”. The military time format uses two digits (00–23). ^[1]
• Applying the code to outpatient claims: The admission hour code is only required on inpatient bills. Using it on outpatient claims may cause confusion or be ignored by the payer. ^[1] (The transmittal states “Required on inpatient bills only.”)
• Inconsistent time documentation: If the medical record shows an admission time of 06:30 but the claim uses code 05 or 07, auditors may flag a discrepancy. Always match the hour code to the documented time of admission.

Related Codes/Fields

The table below lists all admission hour codes (00–23) as defined in the CMS transmittal, along with the field where they are entered.

Code	Meaning (Military Time)	Field
00	12:00 AM – 12:59 AM	FL 13
01	1:00 AM – 1:59 AM	FL 13
02	2:00 AM – 2:59 AM	FL 13
03	3:00 AM – 3:59 AM	FL 13
04	4:00 AM – 4:59 AM	FL 13
05	5:00 AM – 5:59 AM	FL 13
06	6:00 AM – 6:59 AM	FL 13
07	7:00 AM – 7:59 AM	FL 13
08	8:00 AM – 8:59 AM	FL 13
09	9:00 AM – 9:59 AM	FL 13
10	10:00 AM – 10:59 AM	FL 13
11	11:00 AM – 11:59 AM	FL 13
12	12:00 PM – 12:59 PM	FL 13
13	1:00 PM – 1:59 PM	FL 13
14	2:00 PM – 2:59 PM	FL 13
15	3:00 PM – 3:59 PM	FL 13
16	4:00 PM – 4:59 PM	FL 13
17	5:00 PM – 5:59 PM	FL 13
18	6:00 PM – 6:59 PM	FL 13
19	7:00 PM – 7:59 PM	FL 13
20	8:00 PM – 8:59 PM	FL 13
21	9:00 PM – 9:59 PM	FL 13
22	10:00 PM – 10:59 PM	FL 13
23	11:00 PM – 11:59 PM	FL 13

All codes are derived from the CMS transmittal. ^[1] The MassHealth UB-04 Billing Guide references code sets for the UB-04 but does not list individual hour codes. ^[2]

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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