BCHHC Fundamentals

Medicare Home Health — Four Coverage Criteria

ALL four must be met simultaneously:

1.Homebound: Leaving home requires considerable effort due to illness/injury

2.Skilled service: Requires SN, PT, OT, or SLP

3.Physician's care: Certified plan of care (Form 485) every 60 days

4.Reasonable and necessary: Appropriate for condition and goals

Who Fills OASIS?

Clinician	Can Complete OASIS

|-----------|------------------|

SN (RN/LPN)	✅ Yes
PT	✅ Yes
SLP/ST	✅ Yes
OT	❌ No — cannot independently complete OASIS

OASIS Assessment Types

Type	Trigger	Required Timing

|------|---------|----------------|

SOC (Start of Care)	First skilled visit	Within 5 calendar days
ROC (Resumption of Care)	Returns from inpatient	Within 24 hours
REC (Recertification)	Episode renewal	Near end of 60-day episode
SCIC (Significant Change in Condition)	Acute change, no hospitalisation	Within episode
DC (Discharge)	Last visit	At discharge

ICD-10-CM Key Conventions

•NEC (Not Elsewhere Classified): specific documentation, no specific code

•NOS (Not Otherwise Specified): vague documentation, use unspecified code

•Excludes1: cannot code together — mutually exclusive

•Excludes2: separate conditions — CAN code both if both present

•Code first: underlying condition before manifestation

•Use additional code: add detail (organism, laterality, drug use)

Primary Diagnosis Selection (Home Health)

•Must DIRECTLY relate to the skilled service need

•Must SUPPORT homebound status

•Must be the condition the skilled service is ACTIVELY TREATING

•Wrong primary diagnosis → wrong PDGM clinical group → wrong reimbursement

Fundamentals

What You Need to Know First

These are the building blocks. Master these before moving to intermediate topics. Every expert skipped fundamentals at some point and paid for it later.

Core Concepts

Architecture Overview

Understanding how a system is structured helps you reason about its behaviour. Know the main components, how they interact, and what each is responsible for. Draw it out — if you cannot sketch the architecture, you do not understand it yet.

The Basic Unit of Work

Every technology operates on some fundamental unit: a container, a query, a message, a record, a request. Understanding what this unit is and its lifecycle (creation → processing → completion/failure) explains most of the technology's behaviour.

Configuration Fundamentals

Defaults are chosen to be safe, not optimal. Know the defaults, understand what they mean, and know when to change them. Keep configuration in version control. Separate configuration from code.

Error Handling Basics

Read error messages completely — they almost always tell you exactly what is wrong. Know where logs are and how to read them. Understand the difference between transient errors (retry) and permanent errors (fix the code or config).

OASIS Data Collection Protocol

Start of Care (SOC)

The SOC OASIS captures baseline functional status when a patient first begins home health. The clinician assesses:

•Functional abilities (ambulation, transferring, bathing, dressing, eating, toileting)

•Cognitive and behavioral patterns

•Pain, vision, hearing, skin integrity

•Medications and medication management ability

•Equipment and supplies needed

OASIS M Codes — High-Yield Items

OASIS Item	What it Captures	PDGM Impact

|-----------|-----------------|-------------|

M1800-M1860	ADL/IADL function	Functional level (Low/Medium/High)
M1021/M1023	Primary/secondary diagnosis	Clinical group assignment
M1033	Risk for hospitalization	Comorbidity adjustment
M0090	Response date	Episode timing

Homebound Status — Documentation Standards

What Qualifies

A patient is homebound when leaving home requires a considerable and taxing effort due to illness, injury, or functional limitation. CMS requires specific documentation:

•The specific limitation (non-weight-bearing, severe dyspnea, cognitive impairment)

•The effort required (requires wheelchair, two-person assist, significant fatigue)

•Not just "patient is weak" or "patient is elderly"

Allowable Absences

Homebound patients may leave for:

•Medical appointments (physician, therapy, dialysis, chemotherapy)

•Religious services

•Adult day care programs

•Infrequent, short duration outings (barber, family event)

These do not break homebound status if documented appropriately.

ICD-10-CM — Quick Reference for Home Health

Code Structure Review

•Positions 1-3: Category (e.g., I50 = Heart failure)

•Position 4: Etiology or body part

•Position 5: Severity or laterality

•Position 6: Additional specificity

•Position 7: 7th character extensions (encounter type, laterality)

Placeholder X

When a code requires a 7th character but has fewer than 6 characters, the letter X fills empty positions:

T45.X1XA — Poisoning by unspecified drugs, accidental (initial encounter)

The first X fills position 4, the second X fills position 5.

BCHHC Certification Prep — Fundamentals