October 1 2025
OASIS Answers
Categories: HHQRP

Understanding Transfers in OASIS: M1850 vs. GG0170

by Lori A. Marmon, PT, MBA, COS-C

Transfer — it sounds simple, right? Just moving from one spot to another. But when it comes to OASIS, few things are ever that straightforward.

When assessing a patient’s safe ability to transfer, clinicians must complete two sets of functional items: Section G: M Items and Section GG: GG Activities. Each comes with its own guidance and rules. Let’s review a concept that frequently arises in the OASIS Answers Blueprint for OASIS Accuracy 2-day training.

What Do OASIS M and GG Transfer Items Have in Common?

Both M and GG function items should reflect the patient’s ability on the day of assessment — that is, within 24 hours immediately preceding the visit, including time spent in the home by the clinician. The key factor is whether the patient can perform the task safely.

Assessment methods include:

Direct observation (the gold standard),
Interview,
Patient/caregiver report, and
Collaboration among care team members.

Key Differences Between OASIS M1850 and GG0170 Mobility Coding

How to Code OASIS M1850 – Transferring

This item captures the patient’s ability to safely complete a global transfer task, which includes:

Moving from a supine position in bed to sitting at the bedside,
Performing a stand-pivot or sliding board transfer to a chair, and
Returning from the chair to bed.

Clinicians must consider:

The amount of human assistance required,
Whether an assistive device was needed,
Any environmental limitations (e.g., if a chair wasn’t close to the bed), and
Any ambulation needs related to the transfer.

How to Code OASIS GG0170 – Mobility (Transfers)

In contrast, GG0170 breaks the concept of transfer into discrete, task-specific activities:

GG0170A – Roll Left and Right
GG0170B – Sit to Lying
GG0170C – Lying to Sitting on Side of Bed
GG0170D – Sit to Stand
GG0170E – Chair/Bed-to-Chair Transfer

For each of these activities, clinicians must capture the type and amount of assistance required — but do not consider whether an assistive device was used. Assistive devices may help reduce the level of human assistance and allow a patient to be coded as more independent.

This task-specific coding allows for a more nuanced view of the patient’s functional ability and may reflect a patient’s ability (more independent or dependent) with a portion of the tasks included in the more global description for M1850.

Example: Comparing OASIS M1850 and GG0170 Coding

Let’s say your patient:

Moves from lying in bed to sitting on the edge independently,
Walks with a walker to a chair in the next room,
Sits and stands from the chair without assistance,
Returns to bed,
But requires minimal human assistance to get their legs back onto the bed.

Coding for M1850:

Due to:

Use of an assistive device, and
Need for minimal human assistance, this patient would be scored as a 2 – Able to bear weight and pivot during the transfer process but unable to transfer self.

Coding for GG0170 (based on same example):

GG0170A – Roll Left and Right = 06. Independent
GG0170B – Sit to Lying = Partial/Moderate Assistance
GG0170C – Lying to Sitting on Side of Bed = 06. Independent
GG0170D – Sit to Stand = 06. Independent

(See Chapter 3 of the OASIS Guidance Manual and CMS Q&As, Category 4b for rationale)

These GG scores reflect a patient who is largely independent, with help needed for only one aspect of mobility, and paint a much different functional picture of the patient based solely on the ACCURATE coding and application of the OASIS guidance for each individual OASIS item!

Why Accurate OASIS Transfer Coding Matters for Clinicians

While consistency in documentation is essential, understanding the distinct guidance and scoring logic behind M1850 and GG0170 is equally critical. Recognizing that these similarly named tasks will often not align in their coding allows clinicians to assess and document functional performance with greater accuracy, efficiency, and clinical insight.

If you found this discussion interesting, insightful, and maybe even fun, consider joining us for an upcoming Blueprint for OASIS Accuracy 2- day training.