The Katz Index of Independence in ADLs, Explained

The Question a Score of "Needs Some Help" Can't Answer

A daughter sits across from a coordinator during intake and says her mother "needs some help bathing, but she's pretty independent otherwise." Six weeks later, a different coordinator picks up the file after a staffing change and reads that same sentence. It could mean the client needs a hand getting into the tub. It could mean she needs to be washed entirely. It could mean it was true in January and hasn't been true since March. None of that is visible in the sentence, and it's the sentence a family and a caregiver are now planning care around.

This is the specific problem the Katz Index of Independence in Activities of Daily Living was built to solve — turning "needs some help" into a documented, comparable, repeatable score. It's the oldest and most widely used ADL scale in aging services, it's public domain, and it takes a few minutes to administer. This article walks through what it measures, exactly how the scoring works, what the resulting number does and doesn't tell you, and where it fits next to the other assessment you'll almost certainly need alongside it.

What the Katz Index of Independence in Activities of Daily Living Measures

The Katz Index of Independence in Activities of Daily Living was developed by Sidney Katz and colleagues and published in JAMA in 1963, and it's credited with introducing the term "activities of daily living" itself to clinical and caregiving language. It measures six basic, physical self-care functions — the tasks a person has to be able to do, or have done for them, every single day regardless of diagnosis:

• Bathing — sponge bath, tub bath, or shower
• Dressing — getting clothes from closets and drawers, and putting them on
• Toileting — going to the toilet, getting on and off, cleaning up
• Transferring — moving in and out of bed or a chair
• Continence — control of bladder and bowel function
• Feeding — getting food from a plate into the mouth (not meal preparation)

Each of these six is scored independently. Notice what isn't on the list: managing money, taking medication, using the phone, doing laundry. Those are more complex tasks that require a different instrument, which we'll get to below. Katz deliberately stays at the level of basic physical self-maintenance — the functions whose loss is most closely tied to needing hands-on personal care.

How Katz Scoring Works

For each of the six functions, the person being assessed is rated on their actual performance — not what they could theoretically do, and not what a family member believes they should be able to do. The classic Katz format rates each function as independent or dependent, and many current adaptations (including the version widely reproduced by the Hartford Institute for Geriatric Nursing's "Try This" series) score each function on a simple three-point scale: Independent, Needs Assistance, or Dependent.

A few scoring conventions matter and are easy to get wrong on a first pass:

• Score what happens, not what's possible. If a client could dress independently but a caregiver dresses her anyway out of habit or time pressure, the accurate score reflects what's actually happening, with a note explaining why.
• Partial help still counts as assistance. A client who can wash her upper body but needs help with her back and legs is not "independent" for bathing.
• Continence includes both bladder and bowel. Assess them together as a single Katz function, not as two separate items.
• Feeding stops at the plate. Cooking and meal prep are IADL territory, not Katz.

Because each function is scored the same way every time, the same client can be scored today, again in 90 days, and again after a hospitalization — and the three results are directly comparable in a way that "needs some help" and "getting worse" never are.

Reading the Score: What 6, 4, and 2 Actually Mean

Once each of the six functions has a rating, the results are typically summarized into a rough functional band. Per the Hartford Institute for Geriatric Nursing's published guidance, a score of 6 indicates full function, a score of 4 indicates moderate impairment, and a score of 2 or lower indicates severe functional impairment. These bands are a starting point for a conversation, not a diagnosis and not a care-level assignment on their own — a client scoring 4 today because of a broken wrist is in a very different situation than a client scoring 4 due to progressive decline, even though the number is identical.

This is where the score earns its keep in practice. A single Katz score is a snapshot. A series of dated Katz scores is a trend line — and a trend line is what actually answers the questions that matter to a family ("is Mom getting worse, and how fast?") and to a licensing reviewer ("did the plan of care reflect the client's actual functional status at the time services were delivered?"). A score with no timestamp attached to it answers neither question.

A Katz score without a date attached to it is a snapshot with no way to prove when it was taken — which is exactly the gap a licensing reviewer or a skeptical family member will find first.

Katz Alongside the Lawton-Brody IADL Scale

Katz measures basic self-care. It deliberately does not measure the more complex tasks required to live independently in a community setting — using a telephone, shopping, preparing food, housekeeping, doing laundry, arranging transportation, managing medication, and handling finances. Those eight domains are the territory of the Lawton-Brody Instrumental Activities of Daily Living (IADL) Scale, published in 1969, scored on a 0–8 range where 8 reflects full independence across all eight domains.

The two scales are meant to be used together, not as alternatives. A client can score a perfect 6 on Katz — fully independent in bathing, dressing, toileting, transferring, continence, and feeding — while scoring very low on Lawton-Brody because she can no longer manage her medication schedule or pay her bills safely. That combination is common in early cognitive decline specifically, where physical self-care is preserved well after instrumental judgment tasks start slipping. If you're building out a full functional picture rather than a single-domain snapshot, our ADL/IADL assessment guide and the deeper walkthrough of the Lawton-Brody IADL scale cover the eight-domain side in the same level of detail as this article covers Katz.

One clarification worth stating plainly: neither instrument is proprietary in the way some newer standardized cognitive or clinical scales are. The Hartford Institute for Geriatric Nursing publishes its Katz "Try This" adaptation for not-for-profit educational and clinical use with attribution, which is why the framework shows up, in slightly varied formats, across so many care organizations. What you should not do is treat that as license to reproduce a genuinely proprietary or licensed instrument (interRAI and MDS-style tools, for example, are a different category entirely, with their own licensing and training requirements).

Why Timestamped, Versioned Scoring Matters

The value of a Katz score compounds when it's tied to a specific date, attached to a specific version of the plan it informed, and retrievable later without editing. A licensing surveyor asking what the plan said at the time of an incident is asking, in effect, for a Katz score with a timestamp that can't have been quietly edited after the fact. A family member questioning whether Dad's care level should change is asking, in effect, to see the trend line, not just the most recent number.

This is the specific gap that a stack of ClientName_Plan_v3_FINAL_2.docx files can't close — file names and "last modified" dates are not an audit trail, and a document that can be edited in place after the fact is not evidence of what was known when. CareWorkbook's plan builder scores Katz ADL and Lawton-Brody IADL assessments directly in the plan, timestamps each one, and locks a dated, immutable snapshot every time a plan is finalized — so the score from three months ago is still the score from three months ago, not a memory of what someone thinks it might have said. No client assessment data is stored on CareWorkbook's servers by design; agencies and independent care managers should still confirm their own documentation and retention obligations with their state licensing authority.

What the Katz Index Doesn't Do

It's worth being direct about the limits. Katz doesn't assess cognition, mood, pain, or medical status — a client can score a full 6 and still be cognitively impaired, in significant pain, or medically unstable. It doesn't substitute for a licensed clinician's evaluation where one is required. And it isn't a medication management tool: the "feeding" function only covers getting food into the mouth, and even where a broader care plan tracks medication reminders alongside ADL scores, that kind of tracking is organizational — a reminder and record-keeping layer, never clinical dosing guidance or a substitute for a prescriber's or pharmacist's instructions.

Putting It Into Practice

If you're assessing ADLs by hand right now, start with the six functions in order, score what you actually observe or what a reliable caregiver reports, date every score, and repeat the same assessment on a consistent schedule rather than only when something goes wrong. Our companion piece on how to assess activities of daily living walks through the interview and observation technique in more detail, and the Katz ADL scoring breakdown goes deeper on edge cases in each of the six functions.

For agencies and independent care managers who want a structured, print-ready starting point rather than building the form from scratch, the ADL/IADL Assessment Pack includes both the Katz and Lawton-Brody frameworks in a ready-to-use template format. And if you'd rather have pieces like this one — on ADL/IADL scoring, home safety assessment, and care plan documentation — land in your inbox as they're published, our newsletter covers exactly that ground.