The Importance of Proper Diagnosis Coding in Home Health Care

Diagnosis coding has always been important in home health care, and continues to be, particularly in light of changes under the new case-mix classification model, the Patient-Driven Groupings Model (PDGM), which is set to become effective January 1, 2020. Once PDGM replaces the Home Health Prospective Payment System (HHPPS), proper documentation, outcome and assessment information set (OASIS) accuracy and correct coding will have a direct impact on episode payment. It’s, therefore, important home health care providers are vigilant about educating their coding staff. 

Following are best practices you can share with your insureds for their home health care staff to follow to ensure coding is done correctly, courtesy of Healthcare Provider Solutions (HPS), which provides financial, reimbursement, billing and clinical consulting to the home care and hospice industries:

  • A physician and/or physician documentation should verify all diagnoses.
  • Diagnoses must align across the chart – claim, POC*/485 and the OASIS.
  • All coding must be in compliance with the official ICD-10-CM coding guidelines.
  • Code symptoms should not be used if they are part of a disease process/condition unless instructed to do so by the coding guidelines. 
  • Do not list diagnoses if resolved.
  • Diagnoses must be accurate and provide a clear picture as to why the patient is receiving home care.
  • Sequencing of the diagnoses should reflect the seriousness of each condition and support the disciplines and services being provided.
  • The primary diagnosis is defined as the “chief reason the patient is receiving home care” and the diagnosis most related to the current home care POC.
  • Secondary diagnoses must have the potential to impact the skilled services provided by the agency and should have an impact on the diagnoses addressed in the POC, if not directly treated.
  • Each ICD-10 code should be entered at its highest level of specificity.
  • “Unspecified” codes should be avoided. If documentation received is not sufficient to establish a more specific code, consult with the physician.

Following are coding issues that indicate red flags to an auditor:

  • Having the same diagnoses present on multiple claims submitted, for multiple patients, all listed in the top six diagnoses and those being case-mix diagnoses. Each patient should be represented individually and according to the seriousness of his or her own disease processes. 
  • Listing every diagnosis on the POC with an exacerbation and/or onset date as the date of recertification or admission to home care services. These dates also should be individualized with each diagnosis coded, and not generalized to one specific date, especially the admission date or recertification date of home care services. Listing these exacerbation/onset dates is no longer a requirement, however, if the agency chooses to list them, they should be accurate.
  • Coding diagnoses that do not occur in the patient’s billing history, other than a code specific to home care, such as an aftercare code or attention to code. These diagnoses, with regard to disease processes, should originate with the physician and be supported in the documentation preventing this issue from occurring.
  • Using acute codes not appropriate for home care claims.
  • Coding manifestation codes as primary.
  • Coding superficial wounds inappropriately. Documentation should clearly support the wound as it is coded on the claim/OASIS/POC.
  • Contradicting documentation as to the type of wound/ulcer being treated. Physician clarification should be sought if the documentation received regarding the type of ulcer is not clear. 
  • Coding cancer diagnoses as acute (active) versus part of the history of the patient. Verify that the documentation from the physician supports cancer as actively being treated and/or not eradicated and does not indicate the patient merely has a history of cancer.
  • Coding diagnoses that are not supported in the POC, medication profile and/or referral documentation.

Note: Under the PDGM, the Centers for Medicare & Medicaid Services (CMS) has identified 43,287 ICD-10 codes (out of 68,000) as valid primary codes and has mapped each to one of the 12 clinical groupings. All other ICD-10 codes are not considered valid primary codes. Using a non-valid code as primary will result in a submitted claim being returned to the agency for code adjustments, which has potential long-term consequences. Regulatory authorities will likely scrutinize agencies that repeatedly submit non-valid codes as primary.