Active diagnoses,
decoded.
Everything you actually need to know about coding Section I — for new admits, quarterlies, and those “is this even active?” questions that keep you up at night.
It’s not a diagnosis dump.
This is the single most important mindset shift for Section I.
Section I records active diagnoses that have a direct relationship to the resident’s:
A diagnosis belongs in Section I if and only if it passes both of these:
- Hypertension with active antihypertensives
- Diabetes managed with insulin or oral agents
- CHF with active diuretics + fluid monitoring
- Depression on an SSRI with active monitoring
- Atrial fibrillation on anticoagulation
- COPD with active bronchodilators or O₂
- CKD with labs being monitored
- Dementia actively affecting ADLs or behavior
- “History of appendectomy” — resolved, no active treatment
- Remote stroke with zero residual deficits
- Old UTI that resolved last quarter
- “History of MI” with no current cardiac treatment
- Childhood asthma not being managed now
- Resolved C. diff (no active treatment/monitoring)
- Any dx last documented by a physician >60 days ago
- Diagnoses documented by nursing only (not MD/PA/NP)
What does “active” actually mean?
CMS never fully defines “active,” which is why this section trips up so many coders. Here’s how to think about it.
The 60-Day Documentation Rule
A physician, PA, or NP must have documented the diagnosis in the medical record within 60 days before the ARD. This doesn’t mean diagnosed in the last 60 days — it means a qualified provider referenced or addressed it within that window.
Acceptable sources: H&P, progress notes, discharge summary, orders, consultation notes. Not acceptable: nursing assessments, care plans written only by nursing, or verbal reports.
The standard assessment lookback is 7 days, but for Section I on a new admit, you’re establishing a baseline. The H&P, hospital discharge summary, and admission orders are your primary sources. These documents carry the physician’s clinical attestation and support your coding as long as the condition is current.
The 7-day lookback still applies for the assessment period, but Section I reflects conditions active at any point in the 60 days before the ARD. You’re checking what’s currently being managed — not just what happened in the last week.
Ask yourself: “Is this diagnosis causing something to happen in this resident’s care right now?” Any YES answer to the following means it’s likely active:
Where to actually find your diagnoses
Work through these sources in priority order. The further down the list, the more you need to corroborate with a physician-authored document.
New admit: building from scratch
For a 5-Day PPS or OBRA Admission assessment, you’re establishing the clinical baseline. This is your most important MDS for PDPM — get Section I right and you protect your PDPM category from day one.
- 1Read the H&P top to bottomDon’t just skim the problem list. Read the assessment and plan. Physicians sometimes note active conditions in the body that don’t appear in the problem list. Highlight every diagnosis mentioned as current or ongoing.
- 2Read the hospital discharge summaryThe “active problems” or “discharge diagnoses” section is your best structured list. The hospital physician has already organized what was active at discharge. Use this to cross-check the H&P.
- 3Pull the admission MARList every medication. For each one, identify the indication. If the indication is a diagnosable condition, it needs physician documentation to support it. Flag any medication without a clear corresponding diagnosis in the chart.
- 4Review physician admission ordersAdmission orders often include diagnoses (e.g., “Admit for skilled PT/OT. Diagnoses: Hip fracture, DM2, HTN, CHF”). These are physician-attributed and fully valid for Section I.
- 5Apply the two-part test to every candidate diagnosisFor each diagnosis from steps 1–4: Is it documented by MD/PA/NP? Is it actively affecting care? If both yes → code it. If no on either → do not code without clarification.
- 6Query the physician for gaps and ambiguitiesMedications without documented diagnoses, vague terms like “altered mental status” or “weakness,” and any condition that seems active but isn’t explicitly documented — all of these need a physician query before the MDS is locked.
- 7Check for PDPM-relevant diagnosesSection I directly affects PDPM clinical categorization. Conditions like septicemia, respiratory failure, or major surgical wounds need to be specifically documented. Don’t miss high-value diagnoses that change your payment category.
- 8Code and document your sourcesKeep a working document showing which diagnoses you coded and what source supported each one. This is your audit trail if CMS or the RAC comes knocking. “H&P dated 3/15, Dr. Smith — HTN, active on lisinopril” is all you need.
The “H&P List of 30 Diagnoses” problem
Physicians, especially hospitalists, routinely carry decades of PMH in their H&P problem lists. You’ll see things like “GERD,” “s/p cholecystectomy 1987,” “seasonal allergies,” and “remote DVT 2009” listed alongside active conditions.
Apply the filter to every single one. “GERD” is only active if they’re on a PPI for it and a physician has recently referenced it as current. “S/p cholecystectomy” is historical — never active. You’re not trying to capture the person’s entire medical history. You’re capturing what’s happening clinically right now.
Quarterly: maintain, update, verify
The biggest mistake on quarterlies is treating Section I like a carry-forward from the last assessment. It isn’t. Every quarter is an independent look at what’s currently active.
- 1Pull the prior MDS Section I as a reference listDo NOT use it as your answer. Use it as a checklist to verify — for each item that was coded, confirm it’s still active. For any condition you’re removing, document why.
- 2Review physician progress notes from the past 60 daysHas the physician recently addressed each diagnosis? If HTN was last mentioned 75 days ago, you may need a current note before you can code it again.
- 3Review the current MARAny medication changes? A discontinued medication may mean the corresponding diagnosis is no longer active. A new medication may indicate a new diagnosis that wasn’t in the previous MDS.
- 4Check for interval eventsHospitalizations, ER visits, new consults, significant change in status — any of these could add new diagnoses or change the status of existing ones.
- 5Identify diagnoses to removeAny condition that resolved, was no longer documented by a physician in the last 60 days, or is no longer being treated/monitored should be removed. Document your reasoning.
- 6Identify diagnoses to addNew conditions diagnosed since the last assessment, new diagnoses from hospitalizations, conditions that were always present but previously under-coded (query the physician to get the documentation in the chart first).
- 7Physician query if neededAny ambiguous or undocumented diagnoses need a query before the ARD locks. Don’t make the same mistake twice — query early.
These rarely drop off because they’re lifelong and continuously managed:
Still requires physician documentation within 60 days of ARD. Don’t assume — verify.
These are time-limited or resolving — reassess each quarter:
Once resolved and treatment complete, remove from Section I at next assessment.
The three questions before you code anything
Run every candidate diagnosis through this decision logic before it hits your MDS.
| Scenario | Code it? | Why |
|---|---|---|
| HTN listed on H&P, patient on lisinopril daily | YES | Active treatment, physician-documented, ongoing |
| “History of MI” — no cardiac meds, no monitoring | NO | Historical only; no active treatment or monitoring |
| MI 3 years ago, currently on aspirin + statin + metoprolol | YES | CAD/post-MI actively managed — code the active dx driving the meds |
| Dementia — affecting ADLs, behavior, and supervision needs | YES | Actively affecting function; must have MD diagnosis in chart |
| UTI resolved last month, currently no antibiotics or symptoms | NO | Resolved episodic condition; do not carry forward |
| CKD Stage 3 — labs monitored quarterly, on dietary restriction | YES | Active monitoring and dietary management = active |
| Septicemia from admission, now resolved on this quarterly | NO | Was active on the admission MDS, not on this quarterly |
| “Weakness” or “failure to thrive” without specific MD dx | QUERY | Need a specific physician-attributed diagnosis; query before coding |
| Depression — on sertraline, physician monitoring mood quarterly | YES | Active treatment and monitoring; code it |
| Old stroke (5 years ago) with residual left hemiplegia affecting ADLs | YES | Residual deficits actively affecting function; physician must document sequelae |
| Type 2 DM — A1c controlled, no meds, diet-controlled only | YES | Active dietary management; physician monitors A1c = active |
| Cancer in remission, no treatment, last oncology note 4 months ago | QUERY | No active treatment + documentation gap >60 days; need current provider note |
Yes — diagnoses do drop off
The MDS isn’t a permanent medical record — it’s a snapshot of current clinical status. Diagnoses fall off when the clinical reality changes.
UTI cleared, pneumonia resolved, acute DVT treated with no ongoing anticoagulation planned, wound healed, post-op condition resolved. Once resolved and no longer affecting care, it’s off.
Even for chronic conditions. If the physician’s last mention of “hypothyroidism” was 90 days ago, you cannot code it without getting a current note. Easily fixed with a brief physician query.
If a medication was discontinued, the corresponding condition is no longer being treated. Unless the physician still documents it as active (e.g., DM managed by diet alone), it may not meet the active threshold.
“Rule out dementia” that was worked up and turned out to be delirium. Once the physician has a clearer picture, update accordingly.
What gets facilities cited
These are the Section I errors that show up in F640, F641, and F644 surveys.
Blanket carry-forward from prior MDS
Opening the last MDS, hitting “carry-forward” on Section I, and calling it done. Surveyors compare assessments. If the same 14 diagnoses appear verbatim across 3 years of quarterlies with no variation, that’s a red flag for rubber-stamping.
Coding diagnoses supported only by nursing documentation
The nursing assessment says “resident has a history of bipolar disorder” but there’s no physician note in the chart attributing it. This is a documentation deficiency. You cannot code it and CMS can cite you for inaccurate MDS completion (F641).
Leaving active diagnoses off the MDS
Under-coding is just as problematic as over-coding. If a resident is on warfarin for afib and you haven’t coded atrial fibrillation, that’s a Section I error. Under-coding also suppresses PDPM payment and affects quality measures.
Using “rule out” diagnoses as confirmed
“R/O Parkinson’s” is not the same as a Parkinson’s diagnosis. Do not code unconfirmed conditions. Query the physician: “Has this diagnosis been confirmed or ruled out?”
Not knowing the Section I item coding nuances
Some items in Section I have specific CMS definitions that differ from general clinical use:
Skipping Section I on Significant Change assessments
A SCSA requires a full MDS including a fresh Section I. When someone is hospitalized, has a new major diagnosis, or has a significant clinical decline, the new assessment must reflect the updated clinical picture.
Query templates that actually get answered
Keep these short, specific, and clinical. Physicians respond to queries that tell them exactly what you need and why it matters. Never ask vague questions.
Section I — At a glance
Source: CMS RAI User’s Manual v1.18.11, Chapter 3, Section I — Active Diagnoses. Written by Jayson Minagawa, BSN, RN, Unit Manager & MDS Coordinator.