US · guidance
CMS Pub. 100-04, ch. 23, § 50.8
Institutional Claim Record Layout for the Ambulance Fee Schedule
This is a physician fee schedule abstract file for ambulance services payment. The CMS will provide the
specific file names when the prices are released. The file name will contain the label AMBFS.
Record Length - 80
Record Format - FB
Block Size - 27920
Character Code - EBCDIC
Sort Sequence - HCPCS, A/B MAC (B), Locality
Field Name Format Position Description
1-HCPCS X(05) 1 - 5 HCFA Common Procedure Coding
System
2- A/B MAC (B)
Number
X(05) 6 - 10
3-Locality Code X(02) 11-12
4-Base RVU 9(4)v99 13 - 18 Relative Value Unit
5-Non-Facility PE
GPCI
9v9(3) 19 - 22 Geographic Adjustment Factor
6-Conversion Factor 9(5)v99 23 - 29 Conversion Factor
7-Urban Mileage 9(5)v99 30 - 36 Urban payment rate or base rate
mileage rate (determined by HCPCS)
8-Rural Mileage 9(5)v99 37 - 43 Rural payment rate or base rate mileage
rate (determined by HCPCS)
9-Current Year 9(04) 44- 47 YYYY
10-Current Quarter 9(01) 48 Calendar Quarter-value 1-4
11-Effective Date 9(8) 49- 56 Effective date of fee schedule file
12-Filler X(24) 57 - 80 Future Use
History
(Rev. 2643, Issued: 01-31-13, Effective: 07-01-13, Implementation: 07-01-13)
Provenance
- Source
- cms.gov
- Retrieved
- 2026-08-25
- Edition
- iom-2026-08-25
- Content hash
287c6873105745f66968ba66747b849e461ab9df0c1d6296218c080b41e10d65
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