Most charges for observation stays that result in an inpatient admission within 3 days of the observation period will be found in the Inpatient file. Two exceptions are described in the CMS Medicare Claims Processing Manual, section 40.3.B.
Outpatient LDS KnowledgeBase Articles
Researchers working with the outpatient claims data are often interested in calculating the amount paid by Medicare for a particular claim. The total Medicare payment typically can be determined either by using the “Claim Payment Amount” (PMT_AMT) or by summing the “Revenue Center Payment Amount” (REVPMT) for each revenue center. However, researchers have found discrepancies in the amounts when comparing these two approaches.
Claims for ambulance services are found in both the Carrier and the Outpatient claims data. The Ambulance Fee Schedule provides the Healthcare Common Procedure Code System (HCPCS) that identify the services.
Beginning in 2008, some hospital provider numbers appearing in the claims contain a “V” in the fifth position of the six-digit Medicare Provider Number. Usually, the fifth position is a number, not a character. These hospital provider numbers appear in the MedPAR, Inpatient and Outpatient files for both RIF and LDS versions. ResDAC recommends that researchers remove these claims.
There are several types of claim-level files that contain outpatient claims; that is, facility claims submitted for care covered under Part B. In this article, three versions of the LDS files are described:
- Outpatient file,
- Outpatient Prospective Payment System (OPPS) file, and
- OPPS Partial Hospitalization file
Please note that the information below applies to the claim-level files, but not to the stay-level file (the LDS MedPAR).