What people mean by the “PDGM approved diagnosis list”
There is no single CMS document titled “approved diagnosis list.” What agencies call the PDGM approved diagnosis list is the set of ICD-10-CM codes that CMS maps to one of the 12 PDGM clinical groups. If a code appears in that mapping, it can be reported as the primary (principal) diagnosis on a home health claim. If it does not, Medicare treats it as an unacceptable primary diagnosis, sometimes called a questionable encounter code, and returns the claim to the provider.
CMS publishes this mapping with the Home Health Grouper software and the supporting files for each annual payment rule. The same files show which secondary diagnoses count toward the comorbidity adjustment. When PDGM launched, analysts reported that about 43,000 ICD-10-CM codes were mapped as valid primary diagnoses, leaving a large share of the code set unusable as the main reason for home care.
Understanding this list is one of the most important skills in home health coding, because the primary diagnosis decides the clinical group, and the clinical group drives a large share of the 30-day payment.
Where to find the official list
The authoritative source is the CMS Home Health Prospective Payment System case-mix grouper page. CMS posts updated diagnosis files there each year, including new codes with clinical group and comorbidity assignments, deleted codes and revised descriptions. The latest file reflects ICD-10-CM codes effective October 1, 2026.
The annual HH PPS final rule also includes supplemental files that list any codes reassigned to new clinical groups or comorbidity subgroups. For CY 2026, CMS recalibrated the comorbidity adjustment using CY 2024 data, producing 20 low comorbidity subgroups and 98 high comorbidity interaction subgroups.
Two timing rules matter. ICD-10-CM changes take effect every October 1, mid-year for home health. Payment rule changes, including group reassignments, take effect January 1. Your EMR and billing software need both updates loaded on time.
The 12 PDGM clinical groups
Every acceptable primary diagnosis maps to one of these groups. The HIPPS code letter appears in the second position of the code.
HIPPS letter | Clinical group | Typical primary reasons for care |
|---|---|---|
A | MMTA – Other | Conditions needing medication management, teaching and assessment that do not fit another MMTA group |
B | Neuro Rehabilitation | Stroke sequelae, Parkinson's disease, multiple sclerosis and similar neurological conditions needing therapy |
C | Wounds | Pressure ulcers, surgical wound complications, non-healing wounds |
D | Complex Nursing Interventions | Infusion therapy, enteral or parenteral nutrition, ventilator care and similar high-intensity nursing |
E | Musculoskeletal Rehabilitation | Joint replacement aftercare, fractures, osteoarthritis and other orthopedic conditions |
F | Behavioral Health | Depression, anxiety, schizophrenia and other mental health conditions |
G | MMTA – Surgical Aftercare | Aftercare following surgery on specified body systems |
H | MMTA – Cardiac and Circulatory | Heart failure, hypertension with heart disease, peripheral vascular disease |
I | MMTA – Endocrine | Diabetes and other endocrine disorders |
J | MMTA – Gastrointestinal and Genitourinary | GI and urinary tract conditions |
K | MMTA – Infectious Disease, Neoplasms and Blood-Forming Diseases | Cancers, sepsis aftercare, anemias and infections |
L | MMTA – Respiratory | COPD, pneumonia, chronic respiratory failure |
MMTA stands for Medication Management, Teaching and Assessment. Six of the 12 groups are MMTA subgroups, which reflects how much home health nursing centers on teaching and monitoring.
Codes that are not accepted as a primary diagnosis
Codes fall off the acceptable list for a few predictable reasons. Knowing these patterns helps intake and coding staff catch problems before the OASIS is locked.
Symptom and sign codes. Many R-codes describe symptoms rather than a diagnosis. Examples include R26.81 (unsteadiness on feet), R26.89 (other abnormalities of gait and mobility) and R53.1 (weakness). The underlying condition that causes the symptom is usually the right primary code.
Vague musculoskeletal codes. M62.81 (muscle weakness, generalized) was one of the most common primary diagnoses before PDGM. It does not group under PDGM. Code the condition that caused the weakness instead.
Status and history codes. Codes such as Z96.651 (presence of right artificial knee joint) or Z91.81 (history of falling) describe a status, not a reason for skilled care. For joint replacement rehab, an aftercare code such as Z47.1 (aftercare following joint replacement surgery) is the appropriate choice when the record supports it.
Manifestation codes. ICD-10-CM marks some codes “code first underlying condition.” Those manifestation codes, such as dementia in other diseases classified elsewhere (F02.8-), can never be sequenced first under the Official Guidelines.
Codes with a more specific alternative. CMS has removed codes from primary acceptance when another ICD-10-CM code describes the condition more clearly.
A common myth is that every unspecified code is unacceptable. That is not true. Many unspecified codes still group. Always check the current file rather than relying on a rule of thumb.
Examples of acceptable primary diagnoses by group
These examples show common patterns. Confirm each code in the current CMS grouper file before billing.
Heart failure (I50.-) generally groups to MMTA – Cardiac and Circulatory.
COPD with acute exacerbation (J44.1) generally groups to MMTA – Respiratory.
Type 2 diabetes codes (E11.-) without a wound focus generally group to MMTA – Endocrine.
Hemiplegia following cerebral infarction (I69.35-) generally groups to Neuro Rehabilitation.
Pressure ulcer codes (L89.-) at qualifying stages generally group to Wounds.
Aftercare following joint replacement (Z47.1) generally groups to Musculoskeletal Rehabilitation.
Encounter for surgical aftercare on specified body systems (Z48.81-) generally groups to MMTA – Surgical Aftercare.
Major depressive disorder (F32.- and F33.-) generally groups to Behavioral Health.
How secondary diagnoses affect payment
The claim can carry one primary and up to 24 secondary diagnoses. Secondary codes do not change the clinical group, but they can add a comorbidity adjustment:
No adjustment: no qualifying secondary diagnosis.
Low adjustment: at least one secondary diagnosis falls into a low comorbidity subgroup.
High adjustment: two or more secondary diagnoses fall into a high comorbidity interaction subgroup, meaning the pair together predicts higher resource use.
That makes complete, accurate secondary coding worth real money. It also creates audit risk if diagnoses are added without documentation. Code every condition that affects the plan of care, and nothing that the record does not support.
How to avoid PDGM diagnosis RTPs
Capture the real reason for referral at intake. Ask the referral source for the specific diagnosis, not just “weakness” or “falls.”
Run the primary code through your grouper before the start of care OASIS is finalized. Many EMRs flag non-grouping codes automatically.
Query the physician or allowed practitioner when the record only supports a symptom code.
Match OASIS items M1021 and M1023 to the claim. Diagnoses on the OASIS and the claim should agree.
Load annual updates on time. Update code sets for October 1 and grouper assignments for January 1.
Use credentialed coders. Coders with BCHH-C or HCS-D credentials know home-health-specific guidance and Coding Clinic advice.
Audit a sample monthly. Look for patterns such as the same clinician repeatedly choosing non-grouping codes.
Why the list matters for revenue
The 2026 national standardized 30-day rate is $2,038.22, but that number is multiplied by the case-mix weight for the period's group. Moving a patient to a more accurate clinical group, when the documentation supports it, can change payment noticeably. So can capturing a legitimate comorbidity interaction. The reverse is also true: an inaccurate primary code can delay payment for weeks while the claim sits in RTP status.
This is where an experienced home health billing company earns its fee. Coding review before the claim is billed protects both revenue and compliance. Agencies comparing home health billing services in USA should ask whether coders validate the primary diagnosis against the current grouper file.
Local context matters as well. Coachella Valley agencies using home health billing services in Palm Springs often see a high share of cardiac and orthopedic aftercare patients among seasonal residents. Texas agencies relying on home health billing services in the Houston area must also survive Review Choice Demonstration review, where diagnosis support is checked before or after payment. Agencies handling home health billing in NYC often manage complex, multi-morbid patients where comorbidity coding is especially important.
TruCare's coders check every primary diagnosis against the current PDGM file before billing. If you want a second set of eyes on your coding, a home health billing service with certified home health coders can audit a sample of recent claims.
FAQs
Is there an official PDGM approved diagnosis list? CMS publishes the ICD-10-CM to clinical group mapping with its Home Health Grouper files. Codes in that mapping are acceptable as primary diagnoses.
What happens if I bill an unacceptable primary diagnosis? Medicare returns the claim to the provider. You must correct the diagnosis, supported by documentation, and rebill.
Are all R-codes unacceptable as primary? Most symptom codes do not group, but always check the current file rather than assuming.
How often does the list change? ICD-10-CM code changes take effect each October 1, and CMS can reassign codes in each calendar-year payment rule effective January 1.
Sources: CMS Home Health case-mix grouper software and diagnosis files; IHA CY 2026 HH PPS final rule summary; Home Care Magazine on PDGM primary codes; Home Health Care News: debunking PDGM primary diagnosis myths.
