2024 MIPS Cost: Lumpectomy, Partial Mastectomy, Simple Mastectomy Measure


This document details the methodology for the Lumpectomy, Partial Mastectomy, Simple Mastectomy measure and should be reviewed along with the Lumpectomy, Partial Mastectomy, Simple Mastectomy Measure Codes List file, which contains the medical codes used in constructing the measure.

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Measure Description

Episode-based cost measures represent the cost to Medicare for the items and services provided to a patient during an episode of care (“episode”). In all supplemental documentation, “cost” generally means the standardized1 Medicare allowed amount,2 and claims data from Medicare Parts A and B are used to construct the episode-based cost measures.

The Lumpectomy, Partial Mastectomy, Simple Mastectomy episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for patients who undergo partial or total mastectomy for breast cancer during the performance period. The measure score is the clinician’s risk-adjusted cost for the episode group averaged across all episodes attributed to the clinician. This procedural measure includes costs of services that are clinically related to the attributed clinician’s role in managing care during each episode from 30 days prior to the clinical event that opens, or “triggers,” the episode through 90 days after the trigger.


Measure Rationale

Breast cancer accounts for 29% of all new cancer diagnoses in women,3 and the adoption and use of screening mammography based on current United States Preventive Services Task Force guidelines4 has resulted in increased rates of detection of early-stage breast cancer and increased demand for curative surgical intervention.5 Identifying high-value breast cancer treatment approaches that maintain patient health outcomes while offering potential health care cost savings is important since breast cancer treatment costs are the highest among all cancer types and are estimated to reach $20 billion by 2020.6 The Lumpectomy, Partial Mastectomy, Simple Mastectomy episode-based cost measure was selected for development based on input from an expert clinician committee—the Oncologic Disease Management - Medical, Radiation, and Surgical Clinical Subcommittee—because of its impact in terms of patient population and clinician coverage, and the opportunity for incentivizing cost-effective, high-quality clinical care in this clinical area. Based on the initial recommendations from the Clinical Subcommittee, the subsequent measure-specific clinician expert workgroup provided extensive, detailed input on this measure.


Measure Numerator

The cost measure numerator is the sum of the ratio of observed to expected7 paymentstandardized cost to Medicare for all Lumpectomy, Partial Mastectomy, Simple Mastectomy episodes attributed to a clinician. This sum is then multiplied by the national average observed episode cost to generate a dollar figure.


Measure Denominator

The cost measure denominator is the total number of episodes from the Lumpectomy, Partial Mastectomy, Simple Mastectomy episode group attributed to a clinician.


Data Sources

The Lumpectomy, Partial Mastectomy, Simple Mastectomy cost measure uses the following data sources:

  • Medicare Part A and B claims data from the Common Working File (CWF)
  • Enrollment Data Base (EDB)
  • Long Term Care Minimum Data Set (LTC MDS)8


Care Settings

Methodologically, the Lumpectomy, Partial Mastectomy, Simple Mastectomy cost measure can be triggered based on claims data from: ambulatory/office-based care centers, outpatient (OP) hospitals, and ambulatory surgical centers (ASC).



The cohort for this cost measure consists of patients who are Medicare beneficiaries enrolled in Medicare fee-for-service and who undergo partial or total mastectomy for breast cancer that triggers a Lumpectomy, Partial Mastectomy, Simple Mastectomy episode.

The cohort for this cost measure is also further refined by the definition of the episode group and measure-specific exclusions (refer to Section 4).



1 Claim payments are standardized to account for differences in Medicare payments for the same service(s) across Medicare providers. Payment standardized costs remove the effect of differences in Medicare payment among health care providers that are the result of differences in regional health care provider expenses measured by hospital wage indexes and geographic price cost indexes (GPCIs) or other payment adjustments such as those for teaching hospitals. For more information, please refer to the “CMS Part A and Part B Price (Payment) Standardization - Basics" and “CMS Part A and Part B Price (Payment) Standardization - Detailed Methods” documents posted on the CMS Price (Payment) Standardization Overview page. (https://resdac.org/articles/cms-price-payment-standardization-overview).

2 Cost is defined by allowed amounts on Medicare claims data, which include both Medicare trust fund payments and any applicable beneficiary deductible and coinsurance amounts.

3 Siegel, Rebecca L., Kimberly D. Miller, and Ahmedin Jemal. "Cancer Statistics, 2016." CA: A Cancer Journal For Clinicians 66, no. 1 (2016): 7-30.

4 Siu, Albert L. "Screening for breast cancer: US Preventive Services Task Force recommendation statement." Annals of Internal Medicine 164, no. 4 (2016): 279-296.

5 Helvie, Mark A., Joanne T. Chang, R. Edward Hendrick, and Mousumi Banerjee. "Reduction in LateStage Breast Cancer Incidence in the Mammography Era: Implications for Overdiagnosis of Invasive Cancer." Cancer 120, no. 17 (2014): 2649-56.

6 Greenup, Rachel A., Rachel C. Blitzblau, Kevin L. Houck, Julie Ann Sosa, Janet Horton, Jeffrey M. Peppercorn, Alphonse G. Taghian, Barbara L. Smith, and E. Shelley Hwang. "Cost Implications of an Evidence-Based Approach to Radiation Treatment after Lumpectomy for Early-Stage Breast Cancer." Journal Of Oncology Practice 13, no. 4 (2017): e283-e90.

7 Expected costs refer to costs predicted by the risk adjustment model. For more information on expected costs and risk adjustment, please refer to Section 4.5.

8 For information on how LTC MDS data are used in risk adjustment, please refer to Section 4.5.

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