Health Insurance Prospective Payment System (HIPPS) rate codes represent specific sets of patient characteristics (or case-mix groups) on which payment determinations are made under several prospective payment systems. Case-mix groups are developed based on research into utilization patterns among various provider types. For the payment systems that use HIPPS codes, clinical assessment data is the basic input used to determine which case-mix group applies to a particular patient. A standard patient assessment instrument is interpreted by case-mix grouping software algorithms, which assign the case mix group. For payment purposes, at least one HIPPS code is defined to represent each case-mix group. These HIPPS codes are reported on claims to insurers.Institutional providers use HIPPS codes on claims in association with special revenue codes. One revenue code is defined for each prospective payment system that requires HIPPS codes. HIPPS codes are placed in data element SV202 on the electronic 837 institutional claims transaction or in Form Locator (FL) 44 ("HCPCS/rate") on a paper UB-04 claims form. The associated revenue code is placed in data element SV201 or in FL 42. In certain circumstances, multiple HIPPS codes may appear on separate lines of a single claim.
source http://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/ProspMedicareFeeSvcPmtGen/Downloads/hippsusesv4.pdf, accessed June 10 2014.