For a complete review of systems, document at least 10 systems; extended needs 2–9; problem-pertinent needs 1.
Clinicians and coders ask this often because chart rules vary by setting. The short answer lives in the classic E/M documentation playbook, with a modern twist. Legacy guidelines set minimum counts for the review of systems (ROS). Newer office rules shifted code selection to medical decision making or time. This guide lays out the counts, when they apply, and how to document cleanly without fluff.
What The Review Of Systems Includes
ROS is an inventory of body systems recorded from patient answers. The common standard recognizes 14 systems: constitutional, eyes, ears–nose–mouth–throat, cardiovascular, respiratory, gastrointestinal, genitourinary, musculoskeletal, integumentary, neurological, psychiatric, endocrine, hematologic/lymphatic, and allergic/immunologic. Your note credits one system each time you record distinct signs or symptoms for that system, including pertinent negatives when relevant to the visit.
Counts That Define Each ROS Level
Legacy E/M rules describe three levels. Count the number of systems you review and document:
| ROS Level | Definition | Minimum Systems |
|---|---|---|
| Problem-Pertinent | Only the system related to the current problem | 1 |
| Extended | More than one, but not near full breadth | 2–9 |
| Complete | Broad scan across systems | 10 or more |
Those counts come from the long-standing 1995/1997 documentation standards many payers still use. Office and other outpatient visits changed in 2021, which affects when the counts drive the code.
How Many ROS Items Are Needed For Coding Today?
For office and other outpatient visits, the 2021 revision moved code selection to either medical decision making or total time on the date of service. A “medically appropriate” history is still expected, yet you no longer pick a level by tallying ROS bullets in that setting. Emergency care, inpatient services, and many payer audits still reference the older count model, so the minimums in the table above remain part of daily documentation for plenty of charts.
Two extra points keep charts safe. First, when you bill under 1995/1997 rules, a single statement such as “all other systems negative” can bring you to the 10-system threshold once you have individually documented the system related to the problem and any other pertinent systems. Second, you must list positives and any relevant negatives for the systems you count; boilerplate alone does not earn credit.
Where These Numbers Come From
You can read the original language in the CMS 1995 documentation guidelines and in coding education that summarizes the 10-system threshold and the 2–9 range. The office/outpatient 2021 change is outlined in this AAFP overview of the 2021 outpatient change, which explains why many notes still record ROS while the code level relies on decision making or time.
When The Old Counts Still Drive Audits
Auditors still apply the legacy counts in many contexts: ED visits, hospital services, skilled nursing facility care, and payer reviews of older charts. When a service category keeps the history/exam bullets, use the exact minimums: one system for problem-pertinent, two to nine for extended, ten or more for complete.
Counting Rules That Avoid Downcodes
Clear habits prevent disputes during reviews. The following rules catch the common pitfalls.
Credit Only One Section Per Fact
Do not double count the same symptom in the HPI and again in ROS. Count it once in the correct section. If the note repeats the same item, auditors will still credit it once.
Use Pertinent Negatives Wisely
Negatives tied to the problem help demonstrate medical thinking. “No chest pain” under cardiovascular or “no dyspnea” under respiratory can be counted when they inform the encounter. Random negative statements without clinical link add words without value.
Document The Problem System Individually
The “all other systems negative” shortcut works only after you have described the problem system and any other systems that matter to the case. List the problem system in full sentences rather than a single word tag.
Name The System In The Line
State the system name to make counting unambiguous. Example: “Cardiovascular: denies palpitations; + exertional fatigue.” Abbreviations can be fine inside your template; still, a clear header removes doubt.
Match ROS Scope To Clinical Need
For a minor, self-limited issue in the office, a focused review may be plenty. For complex complaints or risk-bearing decisions, broaden the review so the note reflects the clinical picture and, where required, meets the 10-system bar.
Audit-Proof Example Lines You Can Reuse
Templates help, yet the words must match the visit. Use the lines below as patterns and edit them to fit the patient story.
Problem-Pertinent Pattern
Cardiovascular: exertional chest pressure, no palpitations today. Respiratory: no cough, no dyspnea at rest.
This captures the problem system and a related system that narrows differentials during a chest pain visit.
Extended Pattern
ENT: sore throat with odynophagia. Respiratory: dry cough, no wheeze. GI: no nausea, no vomiting. Constitutional: subjective fever last night.
This reaches four systems, enough for extended credit when a count is required.
Complete Pattern
Constitutional: fatigue; afebrile this week. Eyes: no diplopia. ENT: no sinus pressure. Cardiovascular: intermittent palpitations. Respiratory: mild dyspnea on stairs. GI: normal appetite, no melena. GU: no dysuria. Musculoskeletal: morning stiffness in hands. Skin: no new rashes. Neuro: no focal weakness. All other systems negative.
This meets the 10-system threshold while keeping each line short and readable.
Pre-Sign Checklist
- Does the note show the problem system with enough detail to understand the complaint?
- Are counted systems tied to the case rather than boilerplate?
- Is “all other systems negative” used only when a broad review makes clinical sense?
- Are staff-entered ROS answers reviewed and confirmed in your voice?
- Does the rest of the chart (HPI, exam, plan) align with the scope of ROS?
Quick Scenarios That Show The Counts
Office Visit For Viral URI
HPI details congestion and sore throat. ROS records ENT symptoms in detail, adds respiratory cough status, and denies fever. That is two systems. Billing level comes from decision making or time under 2021 rules, not the two-system tally.
ED Visit For Syncope
HPI details the event. ROS lists constitutional, cardiovascular, respiratory, neurological, GI, musculoskeletal, endocrine, hematologic, psychiatric, and ENT. Add “all other systems negative.” That reaches 10 systems and yields a complete review backing a high-level ED service when the rest of the note aligns.
Hospital Medicine Admission For Chest Pain
Broad ROS captures cardiovascular, respiratory, GI, constitutional, neurological, musculoskeletal, psychiatric, endocrine, hematologic, and allergic history. The count exceeds nine, and the language includes key negatives such as no radiation to jaw or arm, no syncope, and no hemoptysis. The note reflects the risk profile for that presentation.
Coder Corner: Payer Variations To Watch
Most audits still use the same math for ROS counts. A few payer policies tweak language around blanket negatives or prefer system-named headers on every line. When you are unsure, follow the strict version: spell out the problem system, add any other pertinent systems, reach 10 only when the case warrants that breadth, and avoid copy-paste blocks that do not match the complaint.
What The 14 Systems Include
The list below mirrors the standard set in coding education and payer references. Use it as a quick checklist during documentation.
| System | Typical Questions Or Findings | Tip |
|---|---|---|
| Constitutional | fever, weight change, chills, fatigue | Trend weight and fever patterns |
| Eyes | vision change, pain, discharge, redness | Note unilateral vs bilateral |
| Ears/Nose/Mouth/Throat | ear pain, congestion, sore throat | Comment on hearing or hoarseness |
| Cardiovascular | chest pain, palpitations, edema | Pair symptoms with exertion or rest |
| Respiratory | cough, dyspnea, wheeze, sputum | Record triggers and relief |
| Gastrointestinal | nausea, vomiting, diarrhea, pain | Map pain location and timing |
| Genitourinary | dysuria, frequency, hematuria | Add pregnancy or prostate context when relevant |
| Musculoskeletal | joint pain, stiffness, swelling | Specify joint and function impact |
| Integumentary | rash, lesions, pruritus | Describe distribution and onset |
| Neurological | headache, weakness, numbness, syncope | Note focal vs diffuse |
| Psychiatric | mood, sleep, concentration | Include safety screening when appropriate |
| Endocrine | polyuria, polydipsia, heat/cold intolerance | Add recent steroid use if relevant |
| Hematologic/Lymphatic | easy bruising, bleeding, lymph node change | State anticoagulant use if present |
| Allergic/Immunologic | seasonal symptoms, hives, recurrent infections | List known triggers or exposures |
Why You Still Record ROS In Office Visits
Even with the 2021 shift, a focused review shows clinical thinking and helps communication with colleagues. It also feeds quality efforts that rely on symptom tracking. Code selection rests on medical decision making or time, yet a concise review still earns its space in the note.
Method And Sources
This guide reflects the counts published in long-standing E/M documentation references and the change that moved office code selection to decision making or time in 2021. For the original wording on the 10-system threshold and on “all other systems negative,” see the CMS documentation standards. For a plain-language summary of extended versus complete counts, see coding education from national bodies, and for the 2021 shift in office visits, see physician society explainers.