UB04 Field 9: Patient Address

Overview

Field 9 on the UB-04 claim form captures the patient’s mailing address. The requirement to report this field varies by payer. The Centers for Medicare & Medicaid Services (CMS) mandates that the provider enter the patient’s full mailing address, including street number and name, post office box number or rural free delivery (RFD), city, State, and ZIP Code ^[1]. This requirement is reinforced by CMS transmittal R1915CP, which states “FL 9 - Patient’s Address Required” ^[2]. In contrast, the Maryland Medicaid program designates the field as Optional, noting that providers may enter the patient’s complete mailing address on lines 1a through 2e (street, city, state, ZIP, and country code if other than USA) ^[3]. Therefore, while the field is optional for Maryland Medicaid, it is required for Medicare Part A and Part B claims. Providers should follow the specific instructions of the payer being billed.

When to Use

Use Field 9 whenever the payer requires a patient address. For Medicare claims, CMS explicitly states the field is mandatory; failure to include an accurate address may result in claim rejection or processing delays ^{[1] [2]}. For Maryland Medicaid, the field is optional, but including the patient’s full mailing address (street or P.O. Box, city, state, ZIP, and country code if not USA) can improve mailing of remittance advice and coordination of benefits ^[3]. The field is used in both inpatient and outpatient settings, but the required status is payer‑driven rather than setting‑driven. When the patient’s address differs from the subscriber/insured’s address, the patient address should still be entered in Field 9, while the subscriber address (if different) may appear in other fields. For newborns, use the newborn’s full address (usually the mother’s address) as the patient’s address. Always verify payer‑specific requirements before submitting.

Step-by-Step Claim Example

Assume a Medicare claim for a patient named Jane Doe. The provider must enter the patient’s full mailing address in Field 9 ^[1]. Using the CMS‑recommended format, the address is:

• Line 1a: 123 Main Street
• Line 2b: Springfield
• Line 2c: IL
• Line 2d: 62701
• Line 2e: (blank if USA)

For a Maryland Medicaid claim, the field is optional, so the example could be omitted, but if included, follow the same structure: “Optional. Enter the patient’s complete mailing address, as follows: Line 1a – Street (or P.O. Box), Line 2b – City, Line 2c – State, Line 2d – Zip, Line 2e – Country Code (Report if other than USA)” ^[3]. Thus, the entry for a Maryland claim would be identical but discretionary. Ensure the address matches the patient’s record; do not use a temporary or facility address unless it is the legal mailing address. Always verify that the ZIP code is correct to avoid return of correspondence.

Common Mistakes & Audit Red Flags

Common mistakes include omitting the address on Medicare claims, which will cause a front‑end edit and possible rejection because CMS requires the field ^[2]. Another error is using an incomplete address (e.g., no street number, missing ZIP code). CMS specifically requires “street number and name, post office box number or RFD, city, State, and ZIP Code” ^[1]. Putting the patient’s name again in the address line is also a red flag. For Maryland Medicaid, providers sometimes incorrectly treat the field as required when it is optional, or vice versa; always verify the payer’s instruction ^[3]. Auditors may notice address mismatches between Field 9 and the patient’s demographic record, indicating potential duplicate billing or fraud. Also, failing to include a country code for non‑USA addresses (as Maryland requires if other than USA) can cause processing errors. Consistently use the patient’s permanent mailing address, not the hospital’s address.

Related Codes/Fields

Use the table below to connect Field 9 with other UB-04 fields that identify the patient and their demographics.

Field	Name	Relationship to FL 9	Source Reference
FL 08a	Patient Name – Identifier	Optional ID that may differentiate patient from subscriber; address in FL 9 should match patient name.	[3]
FL 08b	Patient Name	Required; address should correspond to this patient’s legal name.	[3]
FL 10	Patient Birth Date	Used with address to verify patient identity; both are required by CMS if address is required.	[1]
FL 11	Patient Sex	Not required but often combined with address for demographic consistency.	[3]
FL 12	Admission/Start of Care Date	Ensures the patient was present at the address during service period; date must fall within FL 6 dates.	[3]

These fields together create a complete patient identification block on the UB-04. Always cross‑verify the address in FL 9 with the patient name in FL 08b and the birth date in FL 10 to prevent clerical errors that could trigger audits.

---

References

[1] CMS Chapter 25 — FL 9 — https://www.cms.gov/regulations-and-guidance/guidance/manuals/downloads/clm104c25.pdf

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

[3] Maryland Medicaid — FL 9 — https://health.maryland.gov/mmcp/provider/Documents/ffs-billing/UB04-Hospital-Billing-Instructions%20%281%29.pdf