Home Health Coding and OASIS Expert

OASIS-C1/ICD-10:

Prepare for OASIS-C1/ICD-10 Changes to Diagnosis Coding

Once-powerful M1025 loses its payment impact.

Now that it’s full speed ahead for ICD-10, it’s time to tweak the OASIS-C1 for the new code set. Take a tour of the changes proposed to the diagnosis coding items so you’re read when the big day arrives.

Originally planned to debut with the OASIS-C1, the Centers for Medicare & Medicaid Services put on hold changes to the diagnosis coding OASIS items when ICD-10 implementation got bumped from Oct. 1, 2014, to Oct. 1, 2015. Now the agency is seeking Office of Management and Budget approval for its OASIS-C1/ICD-10 form that includes the updated diagnosis coding M items.

OASIS-C1 Diagnosis Items

Prepare for New Diagnosis Coding Items

As expected, the main change to the diagnosis coding items is the expansion to accommodate ICD-10’s seven character codes in the OASIS-C1/ICD-10. This change means it’s time to say goodbye to M1020/M1022/M1024 and hello to M1021/M1023/M1025. M1025 will also get a new description, moving from M1024’s “Payment Diagnoses” to “Optional Diagnoses.”

With the transition to ICD-10, diagnosis items M1011 (Inpatient Diagnosis), M1017 (Diagnosis requiring medical or treatment regimen change within the past 14 days), and M1025 all forbid the use of V, W, X, Y, and Z codes, while V, W, X, and Y codes are off limits for item M1021 (Other diagnoses). 

In ICD-10, you’ll use V, W, X, and Y codes to report external causes of injuries and other adverse effects — similar to ICD-9’s E codes. You’ll use Z codes, like you did V codes in ICD-9 for reporting the reason for an encounter. You can report Z codes as primary or secondary diagnoses.

Get To Know Optional Diagnoses Item M1025

Although M1025, the new Optional Diagnoses item, has lost the power that M1024 (Payment Diagnoses) wielded, this item hasn’t been removed entirely. After many home health agencies expressed concerns about the need to report diagnoses that aren’t current, but that impact why the agency is providing care, CMS opted to keep M1025 in the OASIS-C1/ICD-10.

So, M1025 lives on, but this item will no longer impact payment.

Originally, OASIS item M1024 was used to list diagnoses that were replaced by V codes in M1020 or M1022 that could have a payment impact. But as of Jan. 1, 2013, this item was limited to fracture codes only, in situations where an agency is providing aftercare for a healing fracture.

After Oct.1, you’ll have no need to report fracture codes replaced by V codes because reporting care for fractures in ICD-10 is completely different from the way it’s done in ICD-9. Instead of reporting a separate aftercare V code, you’ll list the code for the fracture itself with a seventh digit that indicates this is a subsequent encounter.

The directions for Column 3 of M1025 advise:

“There is no requirement that HHAs enter a diagnosis code in M1025 (Columns 3 and 4). Diagnoses reported in M1025 will not impact payment but may be used to risk adjust quality measures Agencies may choose to report an underlying condition in M1025 (Columns 3 and 4) when:

  • a Z-code is reported in Column 2 AND
  • the underlying condition for the Z-code in Column 2 is a resolved condition. An example of a resolved condition is uterine cancer that is no longer being treated following a hysterectomy.”

Column 4 of M1025 is also optional. CMS instructs:

“If a Z-code is reported in M1021/M1023 (Column 2) and the agency chooses to report a resolved underlying condition that requires multiple diagnosis codes under ICD-10-CM coding guidelines, enter the diagnosis descriptions and the ICD-10-CM codes in the same row in Columns 3 and 4. For example, if the resolved condition is a manifestation code, record the diagnosis description and ICD-10-CM code for the underlying condition in Column 3 of that row and the diagnosis description and ICD-10-CM code for the manifestation in Column 4 of that row. Otherwise, leave Column 4 blank in that row.”