ICD-10 · Coding

PDGM Primary Diagnosis Eligibility

Search by ICD-10-CM code or by condition. Get the PDGM clinical group CMS assigns, the comorbidity subgroup, and whether the code holds up in the primary position.

ICD-10-CM FY2026 · CMS grouper v07.1.26

Pick a code on the left to see the PDGM clinical group CMS assigns it, the comorbidity subgroup, and whether it holds up in the primary position.

Every answer comes from the CMS grouper crosswalk — the same table Medicare runs a claim through.

What this tool answers

Under PDGM, the diagnosis you put in the primary position decides which of the twelve clinical groups a 30-day period falls into — and roughly 41% of ICD-10-CM codes are assigned to no clinical group at all. Put one of those in first and the claim comes back as a Return to Provider, unpaid, before anyone reviews the care. This checker reads the CMS grouper crosswalk directly, so for any code it gives you the clinical group CMS actually assigns, the comorbidity subgroup, and whether CMS flags the code as unacceptable or too unspecified to lead a claim.

How to read the result

Chapter
Which of the 22 ICD-10-CM chapters the code sits in. Chapters are ranges, not categories of severity — the chapter is what drives the grouping, which is why two codes that sound clinically similar can behave very differently on a claim.
PDGM clinical group
The group CMS assigns to this exact code, taken from the grouper crosswalk rather than inferred from the chapter. That distinction matters: a stroke and heart failure share ICD-10 chapter 9, but CMS puts the stroke in Neuro Rehabilitation and the heart failure in MMTA - Cardiac. "No clinical group assigned" means a period cannot be grouped from this code at all.
Comorbidity subgroup
Secondary diagnoses can raise payment through the comorbidity adjustment, but only when they fall into a recognised subgroup. This shows which subgroup the code belongs to, or that CMS assigns it none.
Return-to-provider risk
Built from the flags CMS sets on the code — unacceptable in the primary position, too unspecified, a manifestation that needs its underlying condition coded first, or an external-cause code. A high flag is a prompt to find a more specific code before you bill.

Common questions

Does this tool tell me the code is definitely payable?

It reads the same crosswalk Medicare runs your claim through, so the clinical group and the flags are what CMS says. It is not a full claim adjudication: grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list. Treat it as an authoritative answer about the code, not a guarantee about the claim.

Why does the primary diagnosis matter so much under PDGM?

Clinical group is one of the five things that decide the payment group for a 30-day period, alongside admission source, timing, functional impairment level and comorbidity adjustment. The primary diagnosis is what sets the clinical group, so it is the one coding decision with the most direct effect on what the period pays.

What actually happens on a Return to Provider?

The claim is returned unpaid rather than denied, so it can be corrected and resubmitted. The cost is time: the period sits unpaid while somebody finds a more specific code, and in an agency with a thin cash position a run of returned claims is felt quickly.

Which version is this built on?

The CMS Home Health Grouper Software v07.1.26, posted February 2026 and effective for periods from April 2026, covering all 74,719 ICD-10-CM codes CMS publishes. The version is stamped on the page. ICD-10-CM updates each October with quarterly addenda, and CMS reissues the grouper alongside it.

Where this comes from

Browse every ICD-10-CM subchapter

All 285 subchapters CMS publishes codes in. Each page lists every code in the range with the PDGM clinical group assigned to it.

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