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Unit Rebate Amount Information

The Centers for Medicare & Medicaid Services (CMS) Medicaid Drug Rebate (MDR) system performs the Unit Rebate Amount (URA) Calculation using the drug manufacturer's pricing. The specific methodology used is determined by statute, and depends upon whether a drug is classified as:

  • Single source ("S" drug category)
  • Innovator multiple source ("I" drug category)
  • Non-innovator multiple source ("N" drug category)
  • Clotting factor drug (CF)
  • Exclusively pediatric drug (EP)

CMS provides this URA information to states as a courtesy; however, drug manufacturers remain responsible for correctly calculating the URA for their covered outpatient drugs.

Statutory Formulas: Rebate Amount Calculation per Unit of Drug

Innovator Drugs – the greater of 23.1% of the Average Manufacturer Price (AMP) per unit or the difference between the AMP and the best price per unit and adjusted by the Consumer Price Index-Urban (CPI-U) based on launch date and current quarter AMP.

Blood Clotting Factors – the greater of 17.1% of the AMP per unit or the difference between the AMP and the best price per unit and adjusted by the CPI-U based on launch date and current quarter AMP.

Drugs Approved by Federal Drug Administration (FDA) Exclusively for Pediatric Indications – the larger of 17.1% of the AMP per unit or the difference between the AMP and the best price per unit and adjusted by the CPI-U based on launch date and current quarter AMP.

Line Extensions – For a drug that is a new formulation (line extension) of a brand name drug that is an oral solid dosage form, the rebate is the amount computed under section 1927 of the Act or, if greater, the product of:

  • The AMP for the line extension drug
  • The highest additional rebate for any strength of the original brand name drug

The total number of units of each dosage form and strength of the line extension drug (section 1206 of The Health Care & Education Reconciliation Act of 2010 (HCERA), which replaced section 1927(c)(2)(C) as added by section 2501(d) of Patient Protection and Affordable Care Act (PPACA))

"S" or "I" Drug Products URA Calculation

For "S" or "I" drugs, the URA is determined through four steps or calculations:

  • The first calculation provides the basic URA
  • The second provides the additional URA
  • The third adds the basic URA and the additional URA together to determine the total URA
  • The fourth compares the total URA and the quarterly AMP to determine whether the total URA exceeds the quarterly AMP

"S" or "I" Line Extension Drug Product URA Calculation

For "S" or "I" line extension drugs the URA is determined through three steps or calculations:

  • The first calculation provides the Standard URA
  • The second provides the Alternative URA
  • The third compares the Standard URA and the Alternative URA to determine the Total URA

View URA calculation example for line extension "S" or "I" drugs.

"N" Drug Product URA Calculation

For "N" drugs, the URA is determined through four steps or calculations:

  • The first calculation provides the basic URA
  • The second provides the additional URA
  • The third adds the basic URA and the additional URA together to determine the total URA
  • The fourth compares the total URA and the quarterly AMP to determine whether the total URA exceeds the quarterly AMP

For additional information, please contact rxdrugpolicy@cms.hhs.gov.

Disclaimer: Please note that the information provided on this web page does not bind or obligate the Centers for Medicare and Medicaid Services (CMS).  The statements included on this web page are intended to provide information on Unit Rebate Amount and Calculations and do not in any way revise or modify the requirements set forth in Section 1927 of the Act, the national drug rebate agreement (NDRA), subsequent program releases, or regulations. 

Page last updated January 22, 2021