Assessing FY 2021 ICD-10-CM Code Updates

Assessing FY 2021 ICD-10-CM Code Updates

By Janice R. Noller, RHIA, CCS, CDIP, CICA

Fiscal year (FY) 2021 ICD-10-CM code changes, effective October 1, 2020, were initially released July 1, 2020 with the final changes released September 1, 2020. The stabilization of codes experienced last year continues, with 485 new codes, including the two COVID-19 pandemic-related codes U07.1 and U07.0 that were effective April 1.

Many of the new codes have additional detail that can be captured, such as laterality of chest wall and back. There are 56 invalid codes (due to expansion) to capture additional detail. The Centers for Medicare and Medicaid Services’ (CMS) hospital Inpatient Prospective Payment System (IPPS) final rule indicates that of the new codes, 29 have been added to the major complication or comorbidity (MCC) list and 93 have been added to the complication or comorbidity (CC) list.

The ICD-10-CM Official Guidelines for Coding and Reporting also have a few updates. The guidelines for reporting COVID-19 and vaping that went into effect earlier this year have now been incorporated into the official document, but not in Chapter 22: Codes for Special Purposes. The COVID-19 and vaping guidelines are in the chapters of the body systems most affected.

There are many new inclusion notes for codes. It will be important to check your code book Tabular List—whether hard-copy or electronic—to verify your code selection.

Notable New Codes

Sickle-cell disease and thalassemia have been expanded with 20 new codes for specific organ involvements such as acute chest syndrome, cerebral vascular involvement, or splenic sequestration. Many of these will be MCCs if they include specific organ involvements or “with crisis.” Here is the list of the Sickle-cell codes that are MCCs:

  • D57.03, Hb-SS disease with cerebral vascular involvement
  • D57.09, HB-SS disease with crisis with other specified complication
  • D57.213, Sickle-cell/Hb-C disease with cerebral vascular involvement
  • D57.218, Sickle-cell/Hb-C disease with crisis with other specified complication
  • D57.413, Sickle-cell thalassemia, unspecified, with cerebral vascular involvement
  • D57.418, Sickle-cell thalassemia, unspecified, with crisis with other specified complication
  • D57.431, Sickle-cell thalassemia beta zero with acute chest syndrome
  • D57.432, Sickle-cell thalassemia beta zero with splenic sequestration
  • D57.433, Sickle-cell thalassemia beta zero with cerebral vascular involvement
  • D57.438, Sickle-cell thalassemia beta zero with crisis with other specified complication
  • D57.439, Sickle-cell thalassemia beta zero with crisis, unspecified
  • D57.451, Sickle-cell thalassemia beta plus with acute chest syndrome
  • D57.452, Sickle-cell thalassemia beta plus with splenic sequestration
  • D57.453, Sickle-cell thalassemia beta plus with cerebral vascular involvement
  • D57.458, Sickle-cell thalassemia beta plus with crisis with other specified complication
  • D57.459, Sickle-cell thalassemia beta plus with crisis, unspecified
  • D57.813, Other sickle-cell disorders with cerebral vascular involvement
  • D57.818, Other sickle-cell disorders with crisis with other specified complication

Autoimmune hemolytic anemia, category D59.1- has been expanded to provide codes for warm, cold, and mixed types.

Eosinophilia, D72.1- has been expanded into codes such as D72.110, Idiopathic hypereosinophilic syndrome [IHES]; D72.111, Lymphocytic variant hypereosinophilic syndrome [LHES]; D72.12, Drug rash with eosinophilia and systemic symptoms syndrome, among others. Eosinophilia of the respiratory system (J82.8-) has also been expanded to capture acute or chronic Eosinophilic pneumonia or Eosinophilic asthma.

Immunodeficiency can now be described as due to drugs (D84.821) or external causes (D84.822).

Cytokine Release Syndrome (CRS) is a systemic inflammatory response that can be triggered by a variety of factors but more recently after treatment with antibody-based therapies such as rituximab, in graft-versus-host disease, and CAR-T cell therapy. CRS will have specific codes for each Grade that classifies the clinical picture and severity of illness in codes D89.831 through D89.835, and D89.839 when the Grade is not specified.

Twenty-one new codes for substance disorders in Chapter 5: Mental, Behavioral and Neurodevelopmental Disorders (F01-F99) will allow the capture of substance withdrawal whether the status is use, abuse, or dependence. For example, these are the new codes for alcohol abuse and use with withdrawal:

  • F10.130, Alcohol abuse with withdrawal, uncomplicated
  • F10.131, Alcohol abuse with withdrawal delirium
  • F10.132, Alcohol abuse with withdrawal with perceptual disturbance
  • F10.139, Alcohol abuse with withdrawal, unspecified
  • F10.930, Alcohol use, unspecified with withdrawal, uncomplicated
  • F10.931, Alcohol use, unspecified with withdrawal delirium
  • F10.932, Alcohol use, unspecified with withdrawal with perceptual disturbance
  • F10.939, Alcohol use, unspecified with withdrawal, unspecified

Other substances also expanded to allow the capture of substance withdrawal for use/abuse were opioids, cannabis, sedative, hypnotic or anxiolytics, cocaine, other stimulants, and other psychoactive substances and can be found in the Tables 6A-6K on the CMS website under the FY 2021 IPPS Home Page.

Cerebrospinal fluid leak can now be differentiated as “spontaneous” or other (G96.00-G96.09). These conditions can also be further classified as cerebral or spinal.

Twenty-eight new codes will provide further granularity for corneal dystrophy (H18.-) including laterality, endothelial, epithelial, granular, lattice, and macular.

Esophagitis and GERD with esophagitis now have separate combination codes for with or without bleeding (review categories K20 and K21).

In Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue, there are eight new codes (M26.6-) to describe arthritis and arthropathy of the Temporomandibular Joint, including laterality.

Osteoporosis with current pathological fracture codes (M80.0- and M80.8-) can now capture encounters for delayed healing, nonunion, malunion, and sequelae. There are 16 new codes for Juvenile Osteochondrosis (M92.-) for laterality, the parts of the tibia, and if both tibia and fibula are involved.

Chronic Kidney Disease (CKD) Stage 3, which is moderate kidney disease, now has additional stages, 3a and 3b. These subdivisions of CKD Stage 3 are differentiated by the GFR value: a = 45 thru 59; b = 30 thru 44. These new codes are not MCCs nor CCs for FY 2021.

In the absence of a definitive liver diagnosis, there are now specific codes to capture elevated transaminase and LDH (R74.0-).

Chapter 16: Certain Conditions Originating in the Prenatal Period has expanded code P91.8, Other specified disturbances of cerebral status of newborn to capture neonatal cerebral infarctions, including laterality.

Chapter 19: Injury, poisoning, and certain other consequences of external causes, has 52 codes to describe such things as abrasions, contusions, blisters, insect bites, and foreign bodies that also include laterality (S20.-) for the front, back, middle wall of the thorax. Fentanyl and Tramadol now have specific codes to capture poisoning (intentional, accidental, assault, undetermined), adverse effects, and underdosing, separate from other synthetic narcotics in the T40.4- category. The T86.8- category includes new codes for complications of corneal transplants such as rejection, infection, and failure.

Chapter 20: External Causes of Morbidity contains a large portion of the new codes (122) to now describe accidents involving standing electric scooters and micromobility conveyances due to the increased use of these conveyances in our communities. Example: A person on an electric scooter runs into the pole of a street sign; code V00.842A would be assigned.

Official Guidelines for Coding and Reporting

The most notable change to the Guidelines for FY 2021 is the addition of the vaping and COVID-19 guidelines from interim guidance of April 1, to final guidance. A new codebook chapter (Chapter 22 Codes for Special Purposes) was also added on April 1 for the new U codes for vaping and COVID-19. The FY 2021 Guidelines have put these specific guidelines into the chapters for the body systems that are primarily affected:

  • U07.0, Vaping-related disorder, is in Chapter 10: Diseases of the Respiratory System.
  • U07.1, COVID-19, is found in Chapters 1: Certain Infectious and Parasitic Diseases, 15: Pregnancy, Childbirth, and the Puerperium, 16: Certain Conditions Originating in the Perinatal Period, and Chapter 21: Factors influencing health status and contract with health services.

Chapter 22 in the official guidelines will refer to the specific sections of these chapters where the detailed guidelines can be found.

To ease the capture of social determinants of health, patient self-reported documentation signed off by a clinician or provider and placed in the health record can now be used to assign codes Z55 – Z65 (I.B.14.).

Alternative diabetic treatments (an example is Trulicity) can be injectable but not insulin. Guidance in Chapter 4: Endocrine, Nutritional, and Metabolic Diseases, states to use Z79.899 for the long-term use of these types of drugs. If the patient is on an oral antidiabetic drug product as well, both Z79.899 and Z79.84 can be assigned.

As were last year’s, this year’s updated codes are manageable, and the additional specificity continues to support the use of healthcare data across the continuum of care. Remember to download and review the complete addenda for the full changes to the alphabetic index and tabular list, as well as the ICD-10-CM Official Guidelines for Coding and Reporting FY 2021.


Baek, Seung Donet al. “Does stage III chronic kidney disease always progress to end-stage renal disease? A ten-year follow-up study.” Scandinavian Journal of Urology and Nephrology. July 4, 2011.

Centers for Disease Control and Prevention. International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM).

Centers for Medicare and Medicaid Services. FY 2021 IPPS Final Rule Home Page.

himabakuro-Vornhagen, Alexander et al. “Cytokine release syndrome.” Journal for ImmunoTherapy of Cancer. June 15, 2018.


Janice R. Noller ( recently retired as the inpatient coding educator for the University of Utah Hospital in Salt Lake City, UT.

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  1. Thank you for giving this opportunity to complete my CEU /

  2. Excellent information. Well presented and complete.

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