Recent ICD-10 Updates Focus on Better Data Collection

April 1, 2021
April 1, 2021

This post excerpts our article, “ICD-10 Updates for 2018 Drill into the Need for Robust Collecting of Hierarchical Data.”

In 2018, there were 473 changes published in the 10TH release, also known as ICD-10. That included 279 new codes, 143 revised codes, and 51 deleted codes (CDC, 2018). The changes began applying to coding on Oct. 1, 2018 and the list in this form will run through Sept. 30, 2019. The number of additions, changes, updates, and removals is a drop-off from previous years, which is to be expected as wholesale change and addition slows down and more fine-tuning moves in to take its place in the ICD-10 system. In addition, this year also marks a major shift within the coding structure to capturing more complete and comprehensive data around chronic conditions as they are treated in all settings vs. just as inpatient issues, says Susan Gurzynski-Wells, MS, RHIA, Senior Product Manager, Revenue Cycle, for HealthStream.

Introducing Hierarchical Condition Categories (HCCs)

“What we’re starting to see is a drilling down into the things affected by Hierarchical Condition Categories, or HCCs. External-cause codes are also expanding,” Gurzynski-Wells says. “In previous years we’ve seen code updates more along the lines of ‘Oops, this didn’t’ fall in the particular place where it should,’ and now we’re seeing more code updates in the line of specificity, and for patient care that’s not provided at an inpatient facility.”

Focusing on Chronically Ill Patients

This type of update reflects how the Centers for Medicare & Medicaid (CMS), through ICD, are attempting to remain fluid as they evolve alongside a constantly shifting healthcare landscape. For instance, the codes published in 2015 were about moving from four digits to seven digits, which meant a great deal of training and retraining around that nuts-and-bolts issue, meant to streamline processing and documentation. This year, the move toward HCCs highlights the need for more thorough documentation around chronically ill patients in treatment and the need to capture those who are not.

The focus on HCCs isn’t surprising, given their history and importance. CMS first implemented them in 2004 to predict costs for treating Medicare Advantage patients, collecting their demographics and codes to determine a patient’s risk adjustment factor. The goal was to ensure that enough money was earmarked to cover a patients’ future medical needs, so HCCs were quickly embedded into all aspects of coding, documentation and reimbursement. (Fernandez, 2017)

Top HCCs

Since that time, the HCC model has been the basis for CMS to reimburse Medicare Advantage and Medicare Part C plans based on member health. Subsequent to the CMS action, the U.S. Department of Health and Human Services (HSS) developed its own, broader methodology for commercial payers, and now CMS uses HCCs when it calculates the total performance score under the Hospital Value-Based Purchasing System. The top HCCs are:

  • Chronic obstructive pulmonary disease
  • Congestive heart failure
  • Vascular disease
  • Cancer
  • Ischemic heart disease
  • Specified heart arrhythmia
  • Diabetes
  • Ischemic or unspecified stroke
  • Angina
  • Rheumatoid arthritis
  • Inflammatory connective tissue disease (Fernandez, 2017)

The article also includes:

  • Push toward improving outpatient, ambulatory documentation
  • Support system evolving to ensure full and proper documentation
  • The Monitor, Evaluate, Assess/Address, and Treat (MEAT) acronym


CDC, “International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM).” Accessed October 15, 2018.

Fernandez, Valerie. “HCCs: The Cost of Chronic Conditions.” February 8, 2017. Accessed October 15, 2018.

Download the full article here.

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