FY2019 ICD-10-CM/PCS – Official Coding Guidelines and Codeset Update – KEY HIGHLIGHTS

The FY 2019 ICD-10-CM and PCS annual codeset update goes into effect October 1, 2018. See Summary and key highlights below:


Codes ICD-10-CM ICD-10-PCS
New 279 392
Deleted 51 216
Revised 143 8

ICD-10-CM: MCC/CC Changes

  • Acute respiratory distress syndrome (ARDS) is a MCC – ARDS has finally joined respiratory failure as a respiratory system MCC which is consistent with the resource intensity and severity of illness associated with the management of ARDS.
  • AIDS has been downgraded from a MCC to a CC – The reclassification to a CC reflects the advances in the management of AIDS. This change will mostly affect cases where patients are admitted with a non-AIDS related condition since it will no longer be classified as a MCC. For cases where patients are admitted with an AIDS related condition, the principal diagnosis will still be AIDS, so the change from MCC to CC will not impact the DRG assignment for these cases.

ICD-10-CM: New surgical wound infection codes

  • Category T81.4 – Infection following a procedure – was a catch-all for surgical wound infections including postoperative sepsis. It has now been expanded to specify the type of infection/depth of surgical incision.
  • Postoperative/postprocedural infections will be classified as follows:
    • 40X- Infection following a procedure, unspecified
    • 41X- Infection following a procedure, superficial incisional surgical site
    • 42X- Infection following a procedure, deep incisional surgical site
    • 43X- Infection following a procedure, organ and space surgical site
    • 44X- Sepsis following a procedure
    • 49X- Infection following a procedure, other surgical site
  • Requires 7th character (A) initial encounter, (D) subsequent encounter, (S) sequela
  • (A) – initial encounter are CCs

ICD-10-CM – Official Coding Guideline Changes (revisions/additions in bold)

  • “With” – The word “with” or “in” should be interpreted to mean “associated with” or “due to” when it appears in a code title, the Alphabetic Index (either under a main term or subterm), or an instructional note in the Tabular List.
    • The “either under a main term or subterm” addition is likely in part due to the significant changes to diabetes coding. Previously conditions such as diabetic gastroparesis required a cause-and-effect linking statement to code diabetic gastroparesis. Now any condition listed under diabetes and subterm “with” are assumed to be due to diabetes unless stated otherwise by the provider.
  • General Guideline No. 14, Documentation by Clinicians Other than the Patient’s Provider, code assignment is based on the documentation by the patient’s provider (i.e., physician or other qualified healthcare practitioner legally accountable for establishing the patient’s diagnosis). There are a few exceptions, such as codes for the body mass index (BMI), depth of non-pressure chronic ulcers, pressure ulcer stage, coma scale, and National Institutes of Health NIH stroke scale (NIHSS).
    • General Guideline No. 14 was previously titled, “14. Documentation for BMI, Depth of Non-pressure ulcers, Pressure Ulcer Stages, Coma Scale, and NIH Stroke Scale”
    • This additional language is not new information to coders, it serves to reemphasize that documentation is based on healthcare practitioners legally accountable for establishing the patient’s diagnosis.
  • For infections following a procedure, a code from T81.40 to T81.43, Infection following a procedure, or a code from O86.00 to O86.03, Infection of obstetric surgical wound, that identifies the site of the infection should be coded first, if known. Assign an additional code for sepsis following a procedure (T81.44) or sepsis following an obstetrical procedure (O86.04). Use an additional code to identify the infectious agent. If the patient has severe sepsis, the appropriate code from subcategory R65.2 should also be assigned with the additional code(s) for any acute organ dysfunction.
    • Revisions in this section reflect the new ‘infection following a procedure’ codes

ICD-10-PCS – Official Coding Guideline Changes

  • New Guideline

B.17 – Transfer procedures using multiple tissue layers B3.17

The root operation Transfer contains qualifiers that can be used to specify when a transfer flap is composed of more than one tissue layer, such as a musculocutaneous flap. For procedures involving transfer of multiple tissue layers including skin, subcutaneous tissue, fascia or muscle, the procedure is coded to the body part value that describes the deepest tissue layer in the flap, and the qualifier can be used to describe the other tissue layer(s) in the transfer flap.

Example: A musculocutaneous flap transfer is coded to the appropriate body part value in the body system Muscles, and the qualifier is used to describe the additional tissue layer(s) in the transfer flap.

  • Revised Guidelines (Revisions in Bold)


“And,” when used in a code description, means “and/or,” except when used to describe a combination of multiple body parts for which separate values exist for each body part (e.g., Skin and Subcutaneous Tissue used as a qualifier, where there are separate body part values for “Skin” and “Subcutaneous Tissue”).

Example: Lower Arm and Wrist Muscle means lower arm and/or wrist muscle.

  • This revision clarifies that “and” does not mean “and/or” when separate codes exist for each body part. When applicable, two codes should be assigned when unique body part codes exist.

B3.7: Control vs. more definitive root operations

The root operation Control is defined as, “Stopping, or attempting to stop, postprocedural or other acute bleeding.” If an attempt to stop postprocedural or other acute bleeding is initially unsuccessful, and to stop the bleeding requires performing a more definitive root operation, such as Bypass, Detachment, Excision, Extraction, Reposition, Replacement, or Resection, then the more definitive root operation is coded instead of Control.

Example: Resection of spleen to stop bleeding is coded to Resection instead of Control.

  • The descriptor “initially” was removed in FY2019

B6.1a – Device

A device is coded only if a device remains after the procedure is completed. If no device remains, the device value No Device is coded. In limited root operations, the classification provides the qualifier values Temporary and Intraoperative, for specific procedures involving clinically significant devices, where the purpose of the device is to be utilized for a brief duration during the procedure or current inpatient stay. If a device that is intended to remain after the procedure is completed requires removal before the end of the operative episode in which it was inserted (for example, the device size is inadequate or a complication occurs), both the insertion and removal of the device should be coded.

  • Ensure the insertion and removal codes are assigned in applicable cases


  1. ICD-10-CM FY 2019 Files, https://www.cms.gov/Medicare/Coding/ICD10/2019-ICD-10-CM.html
  2. ICD-10-PCS FY 2019 Files, https://www.cms.gov/Medicare/Coding/ICD10/2019-ICD-10-PCS.html

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