🏥Home Health Medical Coding
ICD-10-CM FY2026 · A–Z Chapters · Conventions · HIV · Sepsis · Diabetes · HTN Combos · Wounds · OASIS · PDGM · 8 Interview Q&As
🏥 What is Medical Coding & Types
Medical coding converts healthcare diagnoses, procedures, and services into universal alphanumeric codes used for billing, insurance claims, and statistical tracking.
Code Systems Used
- ICD-10-CM — Diagnosis codes (what the patient has)
- CPT — Procedure codes (what was done)
- HCPCS Level II — Supplies, equipment, drugs
- ICD-10-PCS — Inpatient procedures only
- OASIS — Home health patient assessment
Specialisations
- Inpatient (Hospital)
- Outpatient / Physician Office
- Home Health ← our focus
- Hospice
- Radiology
- Oncology
- Emergency Department
- Orthopaedic / Cardiology
Medicare Coverage Basics
| Medicare Part | Covers |
|---|---|
| Part A | Inpatient, long-term care, critical care, home health (also covered) |
| Part B | Doctor services, outpatient, follow-up annual visits |
| Part C | Medicare Advantage — includes all of A and B |
| Part D | Prescription drug coverage |
Medicare eligibility: Age 65+, ESRD (End Stage Renal Disease), ALS, or disability for 2+ years. Medicaid = poverty-based, monthly plan. Hospice = patient terminally ill, expected to die within 6 months.
Home Health Clinicians
Clinicians who fill OASIS
- SN — Skilled Nurse (RN/LPN)
- ST/SLP — Speech Therapist
- PT — Physiotherapist
- OT — Occupational Therapist (cannot fill OASIS)
Home Health Episode
- 60-day episode per SOC
- Patient must be homebound to receive home health services
- OASIS filled at SOC and Discharge
- Each episode = one OASIS to next OASIS
📋 OASIS Assessment Types — SOC, REC, ROC, SCIC
| Type | Full Name | When | What Happens |
|---|---|---|---|
| SOC | Start of Care | Within 5 days of first visit | Opens the 60-day episode. OASIS filled by SN/ST/PT. |
| REC | Recertification of Care | When HH goals not met in 60 days | Extends episode for more 60 days. REC OASIS → discharge OASIS. |
| ROC | Resumption of Care | Patient hospitalised within episode then returns | Within 24hrs of return. Resume OASIS then discharge OASIS. |
| SCIC | Significant Change in Condition | Within 60 days of SOC, acute condition, no hospitalisation | SCIC OASIS done when condition changes significantly. |
🏠 SOC OASIS→
60 days→
REC OASIS→
Another 60 days→
🏠 Discharge OASIS
🏠 Home→
🏥 Hospital (<24hrs)→
Resume OASIS (ROC)→
🏠 Discharge OASIS
↑ This whole cycle is within 60 days of SOC
⚠️ OT (Occupational Therapist) cannot fill the OASIS. Only SN, ST/SLP, and PT can fill OASIS.
🔤 ICD-10-CM A to Z — Complete Chapter Guide
Every ICD-10-CM code starts with a letter that tells you the category. Memorise this A-Z map — it is the foundation of coding speed.
A–B
Infection codes
Cellulitis, UTI, sepsis, HIV (B20), wound infections
C
Malignant neoplasm — cancer
Primary cancer, secondary cancer, metastasis
D
Benign neoplasm + blood conditions
D63 anaemia with malignancy, D64 drug-induced anaemia
E
Endocrine conditions
Diabetes (E08–E13), thyroid, adrenal, vitamin deficiency, hyperlipidaemia
F
Psychological / mental health
Dementia (F01–F03), depression, anxiety, substance use
G
Nervous system + pain management
Neuropathy, Parkinson's, MS, pain — G89
H
Eye and ear diseases
Post-cataract, glaucoma, hearing loss, vertigo
I
Circulatory system
HTN (I10), CHF, CAD, CVA/stroke, MI — very common in HH
J
Respiratory system
COPD (J44), pneumonia (J18), asthma, respiratory failure
K
Gastrointestinal system
GERD, colostomy care, Crohn's, bowel obstruction
L
Skin and tissue
Pressure ulcers (L89), cellulitis, non-pressure ulcers (L97)
M
Musculoskeletal
Arthritis, fracture aftercare, back pain, osteoporosis — very common HH
N
Genitourinary
UTI, CKD (N18), urinary incontinence, nephropathy
O
Pregnancy codes
Complications, childbirth, puerperal — OB codes
P
Newborn conditions
Neonatal sepsis (P36), prematurity, newborn conditions
Q
Congenital malformations
Genetic problems, birth defects
R
Signs and symptoms
Use when no definitive diagnosis — R52 pain, SOB, weakness
S
Traumatic fractures + injuries
Require 7th character: A=initial, D=subsequent, S=sequela
T
Poisoning, adverse effect, underdose
Drug-induced conditions, overdose, underdose, adverse effect
U
COVID-19
U07.1 COVID confirmed, U07.2 COVID unconfirmed
V–Y
External cause codes
Cause of injury — falls, accidents, place of occurrence, abuse
Z
Encounter, history, status codes
Aftercare (Z48), long-term meds (Z79), history codes, artificial joints (Z96)
💡 Home Health most common chapters: I (circulatory), M (musculoskeletal), E (endocrine/DM), G (nervous), L (skin/wounds), Z (aftercare/status)
📖 ICD-10-CM Conventions — Rules Every Coder Must Know
Abbreviations
NEC — Not Elsewhere Classified
- More information about disease is given but NOT in a specific code
- The condition IS classified somewhere else
- Example: DM due to HLD → E11.69, E78.5
- Example: Chemo-induced anaemia → D64.81
NOS — Not Otherwise Specified
- LESS information given — unspecified
- Specific codes exist but documentation is vague
- Example: Pneumonia → J18.9
- Example: Pain → G89.9
- Example: Anaemia → D64.9
Symbols and Punctuation
| Symbol | Meaning | Example |
|---|---|---|
| ( ) Parentheses | Non-essential modifiers — words in brackets do NOT change the code. Code remains same with or without them. | Htn (essential) — "essential" is non-essential modifier, I10 same |
| [ ] Square Brackets | Manifestation code — must be coded WITH the disease (etiology) | Alzheimer's with dementia — Alzheimer's should be coded with dementia [F02] |
| : Colon | After incomplete term — needs one or more of the modifiers to assign code | Bronchitis: acute / chronic / etc |
Instructional Notes — MANDATORY to follow
Includes
- Conditions given under 'includes' note have same code as the parent code
- Example: Acute bronchitis J20 includes — acute and subacute bronchitis
- COPD J44 includes — asthma and COPD J44.89
- Influenza J10 includes — Influenza A, B, C
Excludes 1 — NOT coded here
- Two same/related conditions CANNOT occur together
- Only code B, NOT A when Excludes1 listed
- Example: J45.909 asthma Excludes1 — J30.9 allergic rhinitis
- Example: J44.9 COPD Excludes1 — J42 bronchitis
- Example: I12.9 Excludes1 — I15.0 renal HTN
- Rule: A does NOT mention that B should not be coded — B instead of A
Excludes 2 — Not included here
- Two conditions are NOT part of each other BUT can coexist
- Code from Excludes2 list SHOULD be coded together
- Example: F02 Dementia Excludes2 — F01 vascular dementia (can code both)
- Example: I42 cardiomyopathy Excludes2 — I25.5 ischemic CM (can code both)
- Example: J18 Pneumonia Excludes2 — J69.0 aspiration pneumonia
Code First / Use Additional Code
- Etiology → Manifestation rule
- Etiology (underlying condition) coded FIRST
- Manifestation coded SECOND
- Example: CKD due to DM → E11.22 (DM) first, N18.x second
- Example: Alzheimer's dementia — G30 first, [F02] second
Etiology and Manifestation Convention
Etiology (cause)
coded FIRST
Manifestation (result)
coded SECOND
Etiology is the CAUSE. Manifestation is the RESULTED condition. Cause is first, then manifestation. Common examples: DM → CKD, DM → neuropathy, Alzheimer's → dementia, HTN → CHF.
Additional Conventions
| Convention | Meaning | Example |
|---|---|---|
| And | "And" or "or" — code two different codes for both | TB bone and joint — two separate codes |
| With | Relationship between two conditions = combination code | HTN with CHF — combination code I11.0 |
| See | Main term must be referenced from another main term | Aortic valve — See Regurgitation |
| See also | If specificity not found, check the alternative word given | Intervertebral disc — See also |
| Default code | If type not mentioned, default to Type 2 DM | Just "DM" written → E11.9 (Type 2) |
| Code also | Two codes needed to fully describe the condition | I50.814 — code also I50.2-, I50.3-, I50.4- |
| $P | Primary code in PDGM | Main diagnosis driving the episode |
| IQ | Questionable encounter — cannot be coded first | Cannot use as primary diagnosis |
7th Character Rules in Home Health
| 7th Char | Meaning | When to Use in Home Health |
|---|---|---|
| A | Initial encounter — active treatment | Infection of surgical wound (taking active antibiotics), Wound VAC present |
| D | Subsequent encounter — routine care during recovery | Most home health fracture aftercare, wound healing without complication, NOT taking antibiotics |
| S | Sequela — late effect after active phase | CVA residual deficits (G81, I69 series), adverse effect medication stopped |
⚠️ Most fractures in home health use D (subsequent). Use A only when actively treating (wound vac, active antibiotics). Use S for sequela/late effects.
Placeholder X: If code requires 7th character but is less than 6 characters, use X to fill position. Example: T14.90XA
Sequela (Late Effect)
Sequela = residual effect — a condition produced after the original injury/illness healed. Code the sequela condition first, then the original cause code with S character. Examples: CVA → hemiparesis (I69.354), CVA → dementia, fracture → deformity.
Acute vs Chronic
Acute Conditions
- Short-term disease
- Pneumonia, fever, cold, UTI
- In PMH: Acute conditions do NOT need to be coded
- Only code active or relevant conditions
Chronic Conditions
- Long-term disease — always code
- DM, HTN, CKD, COPD
- In home health: code ALL chronic conditions
- They affect PDGM comorbidity adjustment
🦠 Chapter 1 — Infectious & Parasitic Diseases (A/B codes)
HIV Coding Rules
| Situation | Primary (1°) | Secondary (2°) | 3rd |
|---|---|---|---|
| Patient admitted for HIV-related condition | B20 (HIV disease) | HIV-related condition | — |
| Patient with HIV admitted for UNRELATED condition | Injury/unrelated code | B20 | HIV-related condition |
| Asymptomatic HIV (HIV+, no disease) | Z21 | — | — |
| HIV infection in pregnancy/childbirth | O98.7- | B20 or Z21 | Related condition |
| Encounter for HIV testing | Z11.4 | +ve→Z21 / -ve→Z17.7 | — |
❌ "AIDS" and "HIV Disease" should NOT be coded with Z21. They are coded with B20. Z21 = asymptomatic only (HIV positive, test positive, known positive, no manifestation).
Patient with inconclusive HIV serology (R75) → with no definitive diagnosis or manifestation
Sepsis — Coding Rules
Sepsis=
Blood stream infection+
Organism directly present in blood
| Type | Code Sequence |
|---|---|
| Sepsis only | 1° A41.9 (sepsis) |
| Severe sepsis (organ dysfunction) | 1° A41.9, 2° R65.20 (without septic shock) |
| Septic shock | 1° A41.9, 2° R65.21, 3° organ failure (N17.9) |
| Sepsis MRSA | A41.02 |
| Sepsis MSSA | A41.01 |
| Sepsis E.coli | A41.51 |
Sepsis = also equals organ dysfunction. R65.21 should be coded ONLY when mentioned.
Post-Procedural Sepsis
When patient gets blood stream infection (sepsis) after any procedure/surgery or due to infected surgical wound:
1° T81.4- (infection following procedure)
→
2° T81.44 (sepsis following procedure)
→
3° A41.9 sepsis
Obstetric Post-Procedural Sepsis (C-section wound)
1° O86.0 (infection following OB surgical wound)
→
2° O86.04 (sepsis following OB procedure)
→
3° A41.0 sepsis
Puerperal Sepsis
Sepsis + septic shock complicating abortion, pregnancy, childbirth, puerperium. NOT due to C-section wound.
| Type | Codes |
|---|---|
| Puerperal sepsis | O85, B96.89 |
| Puerperal severe sepsis | O85, B96.89, R65.20 |
| Puerperal septic shock | O85, B96.89, R65.21 |
Newborn Sepsis (younger than 90 days)
| Type | Codes |
|---|---|
| Newborn sepsis | P36, B96.89 |
| Newborn severe sepsis | P36, B96.89, R65.20 |
| Newborn septic shock | P36, B96.89, R65.21 |
❌ A codes should NOT be used for puerperal or newborn sepsis.
Long-term Antibiotic Treatment
Sepsis (or any infection) cannot be coded with active antibiotics if antibiotics are for more than 10 days: Oral antibiotics → Z79.2 | IV antibiotics → Z45.2, Z79.2 | Hospital antibiotics → cannot be coded
💉 Chapter 4 — Diabetes & Endocrine (E codes)
Diabetes Types
| Code | Type | Note |
|---|---|---|
| E08 | DM due to underlying condition | Code underlying condition first, then E08 |
| E09 | Drug/medication-induced DM | Code E09, then adverse effect code |
| E10 | Type 1 DM | Do NOT code insulin separately (E10 implies insulin) |
| E11 | Type 2 DM (default) | Add Z79.84 (oral antidiabetic), Z79.85 (injectable), Z79.4 (insulin) |
| E13 | Post-pancreatectomy DM | E89.1 + E13 + Z90.4 |
Default: If "DM" written without type → always E11.9 (Type 2). DM = Type 2 by default.
DM Complication Codes (EXX = E10/E11/E13)
Kidney (EXX.2-)
- EXX.21 — Nephropathy
- EXX.22 — CKD
- EXX.29 — Other kidney complication
Eye (EXX.3-)
- EXX.36 — Cataract
- EXX.319 — Neuropathy (eye)
- EXX.39 — Other ophthalmology
Neuropathy (EXX.4-)
- EXX.40 — Neuropathy unspecified
- EXX.41 — Mononeuropathy
- EXX.42 — Peripheral neuropathy
- EXX.43 — Gastroparesis
Circulatory (EXX.5-)
- EXX.51 — PVD (peripheral vascular disease)
- EXX.52 — Gangrene
- EXX.59 — Other circulatory
Skin/Other (EXX.6-)
- EXX.621 — Foot ulcer
- EXX.622 — Skin ulcer
- EXX.65 — Hyperglycaemia
- EXX.649 — Hypoglycaemia
- EXX.69 — Osteomyelitis, other
Insulin Issues
- Underdose insulin → T85.6, T38.3X6, EXX
- Overdose insulin → T85.6, T38.3X1, EXX
Hyperlipidaemia
| Code | Type |
|---|---|
| E78.5 | Hyperlipidaemia unspecified |
| E78.00 | Pure hypercholesterolaemia |
| E78.1 | Pure hypertriglyceridaemia |
| E78.2 | Mixed hyperlipidaemia (severity) |
❤️ Chapter 9 — Circulatory System (I codes)
HTN Combination Codes
HTN (I10) almost always has combination codes with CKD and CHF. Never code them separately when combination code exists.
| Condition | Code(s) |
|---|---|
| HTN alone | I10 |
| HTN + Heart Disease (without HF) | I11.9 |
| HTN + CHF | I11.0 + I50.- |
| HTN + CKD stage 1–4/unspecified | I12.9 + N18.1–N18.4/N18.9 |
| HTN + CKD stage 5 or 6 | I12.0 + N18.5/N18.6 + Z99.2 (dialysis) |
| HTN + CKD + DM + Anaemia | I12.9 + E11.22 + N18.x + D63.1 |
| HTN + CHF + CKD stage 1–4 | I13.0 + I50.- + N18.x |
| HTN + CHF + CKD stage 5/6 | I13.2 + I50.- + N18.5/6 + Z99.2 |
| HTN + HD without HF + CKD 1–4 | I13.10 + N18.1–4 |
| HTN + HD without HF + CKD 5/6 | I13.11 + N18.5/6 + Z99.2 |
| Full combo HTN + CHF + DM + CKD 5/6 + Anaemia | I13.2 + I50.9 + E11.22 + N18.5/6 + D63.1 + Z99.2 |
❌ I51 should NOT be coded with HTN heart disease (I11). If CKD surgery done, still give unspecified CKD code — CKD does not resolve.
Heart Failure Types
| Type | Acute | Chronic | Acute on Chronic |
|---|---|---|---|
| HFrEF / Systolic HF | I50.21 | I50.22 | I50.23 |
| HFpEF / Diastolic HF | I50.31 | I50.32 | I50.33 |
| HFrEF + HFpEF combined | I50.41 | I50.42 | I50.43 |
Atrial Fibrillation
AFib Types — code based on severity
- Paroxysmal (Proximal) — less than 7 days
- Persistent — more than 7 days
- Long-standing persistent — 12 months
- Permanent — 1 year+
Myocardial Infarction (MI)
| Situation | New MI | Subsequent MI |
|---|---|---|
| Within 28 days, 2nd MI occurred | New MI code | I22.9 (STEMI) or I22.2 (NSTEMI) |
| After 28 days, new MI | New MI code only | Old MI = I25.2 (PMH) |
| Type | New | Subsequent |
|---|---|---|
| STEMI Type 1 | I21.3 | I22.9 |
| NSTEMI Type 1 | I21.4 | I22.2 |
| Type 2 MI | I21.A1 | — |
| Types 3/4/5 | I21.A9 | — |
| Old MI (PMH) | I25.2 | — |
Cerebrovascular Disease — CVA Coding in Home Health
❌ Do NOT code active haemorrhage/infarction (I60-, I61-, I62-, I63-) in home health. These are acute hospital codes.
✅ In home health — code the SEQUELA (late effect): Sub-arachnoid haemorrhage → I69.0 | Cerebral infarction (CVA) → I69.3 series | Intracranial infraction → I69.2
| Residual Deficit | Meaning |
|---|---|
| Diplegia | Both legs paralysed |
| Hemiplegia | One side of body affected |
| Quadriplegia | Total body paralysis |
| Monoplegia | Only one limb (hand or leg) |
📌 Chapter 21 — Z Codes (Status, Aftercare, History, Long-term Meds)
Long-term Medication Z Codes
Diabetes Medications
- Z79.4 — Insulin
- Z79.84 — Oral antidiabetic
- Z79.85 — Non-insulin injectable antidiabetic
Cardiac / Blood
- Z79.82 — Aspirin
- Z79.01 — Anticoagulant
- Z79.02 — Antiplatelet / antithrombotic
- Z79.1 — NSAID (non-steroidal anti-inflammatory)
Other Medications
- Z79.2 — Antibiotic (oral, more than 10 days)
- Z79.51 — Contraceptive
- Z79.52 — System steroids
- Z79.899 — Other drugs
Cardiac Status Codes
- Z95.0 — Pacemaker
- Z95.1 — CABG status
- Z95.2 — Prosthetic heart valve
- Z95.5 — Coronary stent
- Z95.810 — Defibrillator
Artificial Joint Replacement Status Codes (Z96)
| Code | Joint |
|---|---|
| Z96.61 | Shoulder replacement |
| Z96.62 | Elbow replacement |
| Z96.63 | Wrist replacement |
| Z96.64 | Hip replacement (Right/Left/Bilateral → 1/2/0) |
| Z96.65 | Knee replacement (Right/Left/Bilateral) |
| Z96.66 | Ankle replacement (Right/Left) |
| Z96.69 | Finger replacement |
Ostomy / Artificial Opening Codes
| History (Z93) | Ostomy type | SN Teaching/Attention (Z43) |
|---|---|---|
| Z93.0 | Tracheostomy | Z43.0 |
| Z93.1 | Gastrostomy | Z43.1 |
| Z93.2 | Ileostomy | Z43.2 |
| Z93.3 | Colostomy | Z43.3 |
| Z93.5 | Cystostomy | Z43.5 |
Surgical Wound Aftercare Codes
| System | Code |
|---|---|
| Nervous system | Z48.811 |
| Circulatory system | Z48.812 |
| Respiratory system | Z48.813 |
| Digestive system | Z48.815 |
| Genitourinary system | Z48.816 |
| Orthopaedic surgery | Z47.89 |
| Joint replacement | Z47.1 |
| Surgical amputation | Z47.81 |
| Cancer aftercare | Z48.3 |
| Foley catheter | Z46.6 |
History Codes — When to Use Z85/Z86/Z87
History Coding Rule
- Active condition → code the disease itself
- Resolved but relevant → use history code
- Implant/device in place → add status code (Z95–Z96)
- After 30 days of surgery → give aftercare code
- After 6 months — no need to code fracture
- Acute conditions in PMH → not coded
- Chronic conditions → always code
Common History Codes
- Z85.xx — History of malignant neoplasm
- Z86.73 — History of stroke (CVA) without residuals
- Z86.79 — History of circulatory disease
- I25.2 — Old MI (>4 weeks)
- Z87.01 — History of pneumonia
- Z87.440 — History of UTI
- Z98.89 — History of surgery
🩹 Wounds, Ulcers & Fractures
Fracture Coding
Traumatic Fracture (S codes)
- Due to fall or accident
- 7th character D = subsequent (most home health)
- 7th character A = initial (active treatment)
- 7th character S = sequela
Non-traumatic Fractures
- Neoplasm → M84.5 + C79.51
- Osteoporosis → M80.-
- Periprosthetic → M97.-
After 6 months, no need to code fracture. In home health, most fractures → 7th character D.
Surgical Wound Categories
| Wound Type | Code | 7th Char |
|---|---|---|
| Non-complication surgical wound (well-healing) | Z48.- / Z47.- | — |
| Disruption/dehiscence (wound opened) | T81.3- | A (wound vac present) / D (no wound vac) |
| Infection of surgical wound (taking antibiotics) | T81.4- | A (taking antibiotics) / D (not taking) |
| Sepsis following procedure | T81.44 → A41.9 | — |
Pressure Ulcers (L89)
Pressure Ulcer Stages
- Stage 1 — skin intact, colour change only
- Stage 2 — skin open, epidermis + dermis level
- Stage 3 — open to fat tissue level
- Stage 4 — open to bone level
- Unstageable — covered with eschar/pus, depth unknown
- Deep Tissue Injury (DTI) — skin intact but pressure to bone/muscle → if skin opens, code Stage 3 or 4 directly
Pressure Ulcer Sites (L89)
- L89.0 — Elbow
- L89.1 — Back
- L89.2 — Hip
- L89.3 — Buttock
- L89.4 — Back/buttock/hip
- L89.5 — Ankle
- L89.6 — Heel
- PARTIAL thickness → last code -1
- FULL thickness → last code -2
Code structure: L89 → I (site) → II (laterality) → III (severity/stage)
Non-Pressure Ulcers (L97)
Etiology: DM, PVD, gangrene, venous stasis, post-thrombotic, post-phlebitic, arteriosclerosis of leg. Must assign TWO codes: 1° Etiology code, 2° L97 site code.
| Site | Code |
|---|---|
| Thigh | L97.1- |
| Calf | L97.2- |
| Ankle | L97.3- |
| Heel/midfoot | L97.4- |
| Other foot | L97.5- |
| Other lower leg | L97.8- |
🫁 Chapter 10 — Respiratory System (J codes)
COPD — Umbrella Term
COPD is an umbrella term that includes many respiratory diseases: asthma, COPD, emphysema, bronchitis, chronic bronchiolitis. Code based on the specific combination documented.
| Combination | Code |
|---|---|
| COPD + unspecified asthma | J44.89 |
| COPD + emphysema | J43.9 |
| COPD + specified asthma | J44.9 + J45.- |
| COPD + pneumonia/bronchitis + exacerbation | J44.1 + J44.0 + J18.9 |
Pneumonia Types
Bacterial / Viral / Fungal
- Needs antibiotics
- J18.9 — unspecified organism
- Specific organism codes under J12–J16
Aspiration Pneumonia
- Due to food particles in trachea
- Does NOT need antibiotics
- J69.0
VAP — Ventilator-Associated Pneumonia
- Due to ventilator mask
- J95.851
Respiratory Failure
| Type | Code |
|---|---|
| Unspecified | J96.9 |
| Acute | J96.0- |
| Chronic | J96.1- |
| Acute on chronic | J96.2- |
🎯 Interview Questions — Medical Coding
Medical Coding · BEGINNER
What are the main A–B code types used in home health infection coding?
A codes = infection codes (bacterial, parasitic). B codes = infection codes (viral, other organisms). Chapter 1 covers Certain Infectious and Parasitic Diseases. In home health most common: cellulitis (L03), UTI (N39.0), wound infections (T81.4-), sepsis (A41.9). B codes are also used for organism identification — if patient has localised infection and there is a causal organism, code: 1° localised infection, 2° B code for organism. Common B organism codes: B96.89 (other specified bacterial agents), used with puerperal sepsis.
Medical Coding · BEGINNER
What is the difference between NEC and NOS in ICD-10-CM?
NEC = Not Elsewhere Classified. More information about the disease IS given, but there is no specific code for it. The condition is classified elsewhere in the code book. Example: DM due to HLD → E11.69, E78.5. Chemo-induced anaemia → D64.81.
NOS = Not Otherwise Specified. LESS information is given — documentation is vague or unspecified. Specific codes exist in the book but the documentation does not support using them. Example: Pneumonia NOS → J18.9. Pain unspecified → G89.9. Anaemia unspecified → D64.9.
Memory tip: NEC = more info, not enough specificity in code. NOS = not enough info in the documentation.
Medical Coding · ENGINEER
Explain the Excludes1 vs Excludes2 rule with examples.
Excludes1 = "NOT coded here." Two same or related conditions CANNOT occur together at the same encounter. If condition A has Excludes1 listing condition B, you code B INSTEAD of A — not both together. The note means A does not mention that B should not be coded — but you code B instead. Examples: J45.909 asthma Excludes1 J30.9 allergic rhinitis — code rhinitis separately, not asthma if rhinitis is the issue. J44.9 COPD Excludes1 J42 bronchitis — cannot code together. I12.9 Excludes1 I15.0 — hypertensive CKD excludes renal HTN.
Excludes2 = "Not included here." The two conditions are NOT part of each other but CAN exist together. Code from Excludes2 list SHOULD be coded when the patient has both conditions. Examples: F02 Dementia Excludes2 F01 vascular dementia — can code both if patient has both. I42 cardiomyopathy Excludes2 I25.5 ischemic CM — can code both. J18 pneumonia Excludes2 J69.0 aspiration pneumonia — can code both.
Medical Coding · ENGINEER
What is the PDGM and how does primary diagnosis affect payment?
PDGM = Patient-Driven Groupings Model. Replaced PPS in January 2020. Payment is per 30-day period (not 60-day episode). Each period classified by 5 factors: (1) Timing — early (1st period) or late, (2) Admission source — community or institutional (hospital discharge), (3) Clinical grouping — 12 groups based on primary diagnosis, (4) Functional level — low/medium/high from OASIS items, (5) Comorbidity adjustment — none/low/high from secondary diagnoses.
Primary diagnosis determines clinical grouping. 12 clinical groups: Musculoskeletal Rehab, Neuro/Stroke Rehab, Wound Care, Complex Medical/Surgical, Respiratory, Endocrine, Infectious Disease, Cardiac, Medication Management, Behavioural Health, Immobility, MMTA. Getting wrong primary Dx = wrong clinical group = wrong reimbursement. Always code to the highest specificity for maximum appropriate payment.
Medical Coding · ENGINEER
How do you code HTN with CHF and CKD stage 3 together?
This is a combination code situation. Never code HTN, CHF, and CKD as separate I10 codes when combination codes exist. Step 1: Identify: HTN + HF + CKD (what stage?). Stage 3 = stages 1 to 4 group. Step 2: Apply combination: I13.0 (HTN with CHF and CKD stage 1-4) + I50.- (specify HF type — I50.9 unspecified or I50.22 chronic systolic) + N18.3 (CKD stage 3). If patient also has DM type 2 with CKD and anaemia: add E11.22 (DM with CKD) + D63.1 (anaemia of CKD). If CKD stage 6 (dialysis): add Z99.2 for dialysis status. Rule: According to CKD stage, the HTN combination code changes.
Medical Coding · ARCHITECT
Patient on home health for CHF monitoring also has type 2 DM on insulin, CKD stage 3, and anaemia of CKD. Code the full primary and secondary diagnoses.
Primary diagnosis: I13.0 (Hypertensive heart and chronic kidney disease with HF, CKD 1-4). This is the combination code for HTN + CHF + CKD stage 3. Heart failure type: I50.22 (chronic systolic CHF) — if documented as systolic. Otherwise I50.9. Diabetes with CKD: E11.22 (Type 2 DM with diabetic chronic kidney disease). CKD stage: N18.3 (CKD stage 3). Anaemia: D63.1 (anaemia in CKD). Insulin use: Z79.4 (long-term insulin use). Do NOT code I10 separately — I13.0 already includes the hypertension. Do NOT code N18.3 with I13.0 alone — both needed to specify stage. Full code list: I13.0, I50.22, E11.22, N18.3, D63.1, Z79.4.
Medical Coding · PRODUCTION
A home health patient has a surgical wound dehiscence with wound VAC in place but no infection. What codes do you assign and which 7th character?
Wound dehiscence = disruption of surgical wound (opening of wound). Code: T81.31XA (disruption of external operation wound, not elsewhere classified). 7th character: A because wound VAC is present = active wound care/treatment. If wound VAC NOT present: use D (subsequent encounter). The wound VAC changes the 7th character because it represents active wound management. Secondary codes: Add Z47.89 (aftercare following orthopaedic surgery) or Z48.89 (aftercare following surgery) depending on original surgery type. If wound is infected: T81.4- with A (taking antibiotics) or D (not taking). Key rule: Active wound treatment (wound VAC, active antibiotics) = A. Routine care without active treatment = D.
Medical Coding · SENIOR
How do you handle coding for CVA in home health when the patient had the stroke 3 months ago and has left-sided hemiplegia and aphasia?
Three-month-old CVA = sequela phase in home health. DO NOT code the acute CVA (I60-I63). Code the RESIDUAL DEFICITS as sequela. Step 1: Identify residuals — hemiplegia (left side) and aphasia. Step 2: Determine dominance — if not documented, use non-dominant as default. Step 3: Code the sequela codes from I69.3 series (following cerebral infarction). Hemiplegia left non-dominant: I69.354. Aphasia following cerebral infarction: I69.320. These are the PRIMARY and additional diagnoses for home health. Do NOT add the original stroke code (I63-) — sequela codes already indicate it was post-infarction. If patient had haemorrhagic stroke, use I69.1- (following non-traumatic subarachnoid) or I69.2- (following intracranial) series.