US · guidance
CMS Pub. 100-04, ch. 15, § 20.1.5.1
CMS Supplied National ZIP Code File and National Ambulance Fee
Schedule File
(Rev. 2703, Issued: 05-10-13, Effective: 10-01-13, Implementation: 10-07-13)
CMS will provide each contractor with two files: a national ZIP Code file and a national
Ambulance FS file.
A. The national ZIP5 Code file is a file of 5-digit USPS ZIP Codes that will map each ZIP Code
to the appropriate FS locality. Every 2 months, CMS obtains an updated listing of ZIP Codes
from the USPS. On the basis of the updated USPS file, CMS updates the Medicare ZIP Code
file and makes it available to contractors.
The following is a record layout of the ZIP5 file effective January 1, 2009
ZIP5 CODE to LOCALITY RECORD LAYOUT
Field Name Position Format COBOL
Description
State 1-2 X(02) Alpha State Code
ZIP Code 3-7 X(05) Postal ZIP Code
A/B MAC (B) 8-12 X(05) A/B MAC (B)
Number
Pricing Locality 13-14 X(02) Pricing Locality
Rural Indicator 15 X(01) Effective 1/1/07
Blank = urban,
R=rural, B=super
rural
Field Name Position Format COBOL
Description
Beneficiary Lab CB
Locality
16-17 X(02) Lab competitive bid
locality;
Z1= CBA1
Z2= CBA2
Z9= Not a
demonstration
locality
Rural Indicator 2 18 X(01) What was effective
12/1/06
Blank=urban,
R=rural, B=super
rural
Filler 19-20 X(02)
Plus Four Flag 21 X(01) 0 = no +4 extension
1 = +4 extension
Filler 22-75 X(54)
Year/Quarter 76-80 X(05) YYYYQ
NOTE: Effective October 1, 2007, claims for ambulance services will continue to be submitted
and priced using 5-digit ZIP Codes. Contractors will not need to make use of the ZIP9 file for
ambulance claims.
Beginning in 2009, contractors shall maintain separate ZIP Code files for each year which will
be updated on a quarterly basis. Claims shall be processed using the correct ZIP Code file based
on the date of service submitted on the claim.
A ZIP Code located in a rural area will be identified with either a letter “R” or a letter “B.”
Some ZIP Codes will be designated as rural due to the Rural Urban Commuting Area (RUCA)
Score even though the ZIP Code may be located, in whole or in part, within an MSA or Core
Based Statistical Area (CBSA).
A“B” designation indicates that the ZIP Code is in a rural county (or RUCA area) that is
comprised by the lowest quartile by population of all such rural areas arrayed by population
density. Effective for claims with dates of service between July 1, 2004 and December 31, 2010,
contractors must apply a bonus amount to be determined by CMS to the base rate portion of the
payment under the FS for ground ambulance services with a POP “B” ZIP Code. This amount is
in addition to the rural bonus amount applied to ground mileage for ground transports originating
in a rural POP ZIP Code.
Each calendar quarter beginning October 2007, CMS will upload updated ZIP5 and ZIP9 ZIP
Code files to the Direct Connect (formerly the Network Data Mover). Contractors shall make
use of the ZIP5 file for ambulance claims and the ZIP9 file as appropriate per IOM Pub. 100-04,
Medicare Claims Processing Manual, chapter 1 -General Billing Requirements , section 10.1.1 -
Payment Jurisdiction Among A/B MACs (B) for Services Paid Under the Physician Fee
Schedule and Anesthesia Services and the additional information found in Transmittal 1193,
Change Request 5208, issued March 9, 2007. The updated files will be available for
downloading on approximately November 15th for the January 1 release, approximately
February 15th for the April 1 release, approximately May 15th for the July 1 release, and
approximately August 15th for the October 1 release.
Contractors are responsible for retrieving the ZIP Code files upon notification and must
implement the following procedure for retrieving the files:
1. Upon quarterly Change Requests communicating the availability of updated ZIP Code files,
go to the Direct Connect and search for the files. Confirm that the release number (last 5 digits)
corresponds to the upcoming calendar quarter. If the release number (last 5 digits) does not
correspond to the upcoming calendar quarter, notify CMS.
2. After confirming that the ZIP Code files on the Direct Connect corresponds to the next
calendar quarter, download the files and incorporate the files into your testing regime for the
upcoming model release.
The names of the files will be in the following format:
MU00.AAA2390.ZIP5.LOCALITY.Vyyyyr and MU00.AAA2390.ZIP9.LOCALITY.Vyyyyr
where “yyyy” equals the calendar year and “r” equals the release number with January =1, April
=2, July =3, and October =4. So, for example, the names of the file updates for October 2007 are
MU00.AAA2390.ZIP5.LOCALITY.V20074 and MU00.AAA2390.ZIP9.LOCALITY.V20074.
The release number for this file is 20074, release 4 for the year 2007.
When the updated files are loaded to the Direct Connect, they will overlay the previous ZIP
Code files.
NOTE: Even the most recently updated ZIP Code files will not contain ZIP Codes established
by the USPS after CMS compiles the files. Therefore, for ZIP Codes reported on claims that are
not on the most recent ZIP Code files, follow the instructions for new ZIP Codes in §20.1.5(B).
B. CMS will also provide contractors with a national Ambulance FS file that will contain
payment amounts for the applicable HCPCS codes. The file will include FS payment amounts
by locality for all FS localities. The FS file will be available via the CMS Mainframe
Telecommunications System. Contractors are responsible for retrieving this file when it
becomes available. The full FS amount will be included in this file. CMS will notify contractors
of updates to the FS and when the updated files will be available for retrieval. CMS will send a
full-replacement file for annual updates and for any other updates that may occur.
The following is a record layout of the Ambulance Fee Schedule file:
AMBULANCE FEE SCHEDULE FILE RECORD DESCRIPTION
Field Name Position Format Description
HCPCS 1-5 X(5) Level 2 HCPCs
code number for the
service.
A/B MAC (B)
Number
6-10 X(5) Contractor Number
Locality Code 11-12 X(2) Identification of
Pricing Locality
RVU 13-18 9(4)V2 Relative Value
Units set a numeric
value for ambulance
services relative to
the value of a base
level ambulance
service.
GPCI (PE) 19-22 9V3 The GPCI for the
practice expense
portion of the
Medicare physician
fee schedule is used
to adjust payment to
account for regional
differences.
Base Rate 23-29 9(5)V2 A nationally
uniform “base”
amount used to
calculate each
HCPCS’ payment
amount.
Urban Rate 30-36 9(5)V2 Urban Ground/Air
mileage rate.
Rural Rate 37-43 9(5)V2 Rural Ground/Air
mileage rate.
Current Year 44-47 x(4) 4 digit current
effective year.
Current Quarter 48-48 x(1) 1 digit current
effective quarter:
1=January, 2=April,
3=July, 4 =October.
Current Date 49-56 x(8) Current Effective
Start Date.
Filler 57-80 X(26) Future use
History
(Rev. 2703, Issued: 05-10-13, Effective: 10-01-13, Implementation: 10-07-13)
Provenance
- Source
- cms.gov
- Retrieved
- 2026-08-25
- Edition
- iom-2026-08-25
- Content hash
8966e8b19c0b206a93bc57b9cb93b21abb277b75d0764da8e0f24b6a2d64f54f
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