MCG guidelines (formerly known as Milliman Care Guidelines) are evidence-based clinical decision-support criteria used by healthcare organizations to:
- Evaluate medical necessity
- Determine the appropriate level of care
- Support care management decisions across inpatient, outpatient, behavioral health, and post-acute settings
MCG Health develops and updates these guidelines annually, drawing from peer-reviewed medical literature and systematic evidence review.
Payers, hospitals, and government agencies use MCG guidelines during utilization review to assess whether a requested service, admission, continued stay, or care transition is clinically supported.
In this guide, we’ll be exploring:
- What MCG stands for and how the guidelines evolved
- Who uses MCG guidelines and what care settings they cover
- Whether the guidelines function as rules or recommendations
- How MCG guidelines are used across the utilization review workflow
- A documentation checklist for providers preparing for MCG-based review
What does MCG stand for?
MCG is commonly associated with Milliman Care Guidelines, the original name of the clinical criteria product.
The company now operates as MCG Health, a subsidiary of Hearst Health, and publishes its guidelines under the MCG brand.
In utilization review and care management conversations, “MCG” almost always refers to MCG Health’s evidence-based care guidelines — not the Medical College of Georgia or other uses of the acronym.
For the 28th edition alone, MCG’s clinical editors reviewed 217,640 scientific articles, resulting in 48,137 unique citations in the evidence base (including 5,565 new citations for that release).
How are MCG guidelines used in utilization review?
MCG guidelines support several stages of the utilization management workflow, from the first authorization request through discharge planning and post-acute transitions.
MCG IN UTILIZATION REVIEW
Four review stages where MCG criteria apply
Prior authorization
Pre-service review of planned procedures, imaging, or services
Admission review
Inpatient vs observation status determination at the point of care
Concurrent review
Ongoing reassessment of continued stay need during hospitalization
Discharge planning
Transition decisions to SNF, rehab, home health, or LTACH
Prior authorization
Payers may use MCG criteria to evaluate whether a planned procedure, imaging study, or service meets medical necessity before care is delivered.
Admission review
When a patient arrives at the hospital, utilization review nurses compare clinical documentation against MCG admission criteria to determine whether inpatient care or observation status is appropriate.
Concurrent review
During hospitalization, reviewers reassess the case against continued stay criteria.
Daily documentation should show ongoing clinical need for the current level of care, progress toward recovery milestones, and unresolved barriers to discharge.
Discharge planning
MCG guidelines may support transition decisions, including movement from acute care to skilled nursing, inpatient rehabilitation, home health, or long-term acute care.
The AMA’s 2025 Prior Authorization Physician Survey found that physician practices complete an average of 40 prior authorizations per physician per week — and 26% of surveyed physicians reported that prior authorization had led to a serious adverse event for a patient.
The volume alone shows why structured criteria are embedded so deeply in payer operations (and why the documentation that feeds those criteria carries so much weight).
How does an MCG-based review work in practice?
The review follows a predictable sequence, but the outcome depends heavily on what the clinical record actually contains.
Step 1: Select the appropriate MCG guideline
The reviewer identifies the requested service or care setting, then selects the relevant MCG guideline category based on diagnosis, patient age, and care type.
Step 2: Match clinical documentation to the criteria
Clinical data is pulled from the medical record (symptoms, vitals, lab values, imaging results, failed treatments, functional limitations, and comorbidities) and each element is compared against the applicable criteria.
MCG describes its inpatient care guidelines as:
- Goal length-of-stay benchmarks
- Readmission risk assessment guidance
- Clinical indications for the requested level of care
- Expected recovery and care progression pathways
- Rapid review guidance for inpatient vs observation decisions
Each of these components gives reviewers a structured framework for the decision at hand.
Step 3: Determine approval, escalation, or additional review
If the documented findings meet criteria, the case may be approved at first-level review.
If not, the case moves to a secondary physician review, a request for additional documentation, or a peer-to-peer discussion between the treating physician and the medical director.
A common mistake is treating documentation as an afterthought.
In practice, a medically appropriate case can fail first-level MCG screening because the chart doesn’t capture severity, treatment intensity, or failed lower-level care clearly enough to match the criteria elements.
The care might be justified, but the record doesn’t prove it.
How do MCG and InterQual compare?
MCG (Hearst Health) and InterQual (Optum) are the two dominant proprietary clinical criteria tools in utilization management. Both are evidence-based, both support medical necessity review, and both serve payers, hospitals, and government programs.
| Area | MCG | InterQual |
| Primary function | Evidence-based care guidelines and utilization review | Criteria-based medical necessity and level-of-care review |
| Common users | Payers, hospitals, government entities, TPAs | Payers, hospitals, health systems, government entities |
| Practical reviewer focus | Matching care needs to expected care pathways and recovery timelines | Matching documented findings to specific clinical criteria elements |
| Access | Licensed, proprietary | Licensed, proprietary |
| Often described as | More pathway-oriented and recovery-focused | More granular and condition-specific |
Some utilization review nurses describe MCG as more oriented toward care progression and expected recovery course, while InterQual tends to focus on detailed clinical element matching.
The actual difference often depends on how a specific payer or health system has implemented and configured the tool — not on any inherent superiority of one over the other.
Providers working with multiple payers will likely encounter both. The documentation principles remain largely the same regardless of which tool the reviewer is using.
Who uses MCG guidelines?
MCG guidelines appear across nearly every layer of the utilization management process.
The primary users include
- Medical directors overseeing coverage determinations
- Hospital revenue cycle teams analyzing denial patterns
- Utilization review nurses who screen cases against criteria
- Physician advisors who review cases that fail first-level screening
- Case managers coordinating care transitions and discharge planning
- Payer review teams evaluating prior authorization and continued stay requests
- Government agencies and managed care organizations administering Medicare Advantage and Medicaid programs
MCG states that its solutions are used by hospitals, health plans, and state and federal government agencies. The company also holds URAC Health Utilization Management Clinical Review Criteria certification, effective May 2024 through May 2027.
What types of care do MCG guidelines cover?
MCG guidelines span multiple care settings and clinical categories.
| Guideline area | What it supports |
| Inpatient care | Admission review, level of care, length of stay, recovery planning |
| Ambulatory care | Outpatient procedures and services |
| Behavioral health | Mental health and substance use treatment review |
| Recovery facility care | Skilled nursing, inpatient rehab, LTACH decisions |
| Home care | Home-based care planning and authorization |
| Chronic care | Ongoing care management for long-term conditions |
| Transitions of care | Movement between care settings after hospitalization |
The 29th edition, released in 2025, added five new observation care guidelines:
- A hospital-at-home guideline
- A dedicated gene and cellular therapy section
- A pediatric chronic-care guideline for anxiety disorders
- A pediatric chronic-care guideline for depressive disorders
- A pediatric chronic-care guideline for substance-related disorders
MCG also announced its 30th edition in March 2026, reflecting continued updates tied to evidence-based medicine and AI-enabled content.
Are MCG guidelines rules or recommendations?
MCG guidelines are clinical decision-support tools, not rigid regulations.
They help reviewers and clinicians evaluate medical necessity and care planning, but they are one input among several in any coverage or care decision.
Other factors that may influence the outcome include
- Clinical judgment by the treating physician
- Patient-specific clinical facts and comorbidities
- Payer medical policy and benefit coverage rules
- Quality and completeness of clinical documentation
- Medicare, Medicaid, or state regulatory requirements
CMS’s 2024 Medicare Advantage Final Rule (CMS-4201-F) clarified that MA plans must follow national and local coverage determinations, as well as Traditional Medicare coverage rules, for basic benefits.
When Medicare criteria are not fully established, MA plans may use internal coverage criteria only when based on current evidence in widely used treatment guidelines — and must make those criteria publicly accessible.
The practical implication for providers is clear.
MCG guidelines can support a review decision, but they cannot override Medicare coverage law, payer contract terms, or the clinical realities documented in a patient’s record.
How can providers document for MCG-based review?
Strong clinical documentation is the single most controllable factor in whether a case meets MCG guidelines.
Reviewers can only match what appears in the chart — and a patient’s actual clinical picture is invisible to the review process if the record doesn’t capture it.
A defensible medical record for utilization review should include
- Comorbidities that increase clinical risk
- Why care is needed now rather than at a later date
- Daily progress updates during continued stay review
- Current symptoms and their functional impact on the patient
- What lower-level care was attempted or why it would be unsafe
- Objective findings (vitals, labs, imaging, exam results)
- Expected recovery course and barriers to discharge
- Treatment intensity and monitoring requirements
The biggest documentation gap most teams face isn’t missing information — it’s clinical reasoning that exists in the provider’s head but never makes it into the written record.
| Weak documentation | Stronger documentation |
| “Patient needs admission.” | “Patient requires inpatient monitoring due to persistent tachycardia and new-onset atrial fibrillation unresponsive to rate control.” |
| “Failed outpatient care.” | “Completed 14-day oral antibiotic course with worsening fever, rising WBC, and new infiltrate on chest imaging.” |
| “Needs SNF.” | “Requires daily skilled PT/OT due to measurable decline in mobility and ADL independence following hip replacement surgery.” |
A reviewer evaluating the case days or weeks later cannot assess what was never documented, and by the time the denial arrives, the opportunity for real-time documentation improvement has passed.
What happens when a case does not meet MCG criteria?
Failing first-level criteria review does not mean the patient doesn’t need care.
It means the documented record, as reviewed against the applicable criteria set, did not meet the threshold for the requested level of care.
PRIOR AUTHORIZATION CASCADE
What happens to 52.8 million PA requests
52.8M
Total MA prior auth determinations (2024)
4.1M denied
7.7% denied in full or part
11.5% appealed
Most denials go unchallenged
80%+ overturned
Of those appealed, most are reversed
Source — KFF Medicare Advantage Prior Authorization Report (2026)
From the point of non-match, several paths exist
- The provider submits a formal appeal
- The reviewer requests additional clinical documentation
- A physician advisor or medical director reviews the case
- A peer-to-peer discussion between the treating and reviewing physicians takes place
KFF found that Medicare Advantage insurers made 52.8 million prior authorization determinations in 2024, denying 4.1 million (7.7%) in full or in part. Only 11.5% of those denials were appealed, yet more than 80% of appealed denials were overturned.
A separate HHS-OIG review of 250 prior authorization denials found that 13% of denied requests actually met Medicare coverage rules and would likely have been approved under Original Medicare. Two common causes were:
- The use of clinical criteria not contained in Medicare coverage rules
- Cases where reviewers deemed documentation insufficient despite adequate medical records.
The overturn and error rates tell a clear story. Many denials stem from documentation gaps, overly rigid initial interpretation, or misaligned criteria application.
For revenue cycle teams, the most effective denial prevention strategy starts before the initial review, with documentation that anticipates what a reviewer needs to see.
When clinical criteria decisions affect your revenue
Medical necessity denials tied to MCG guidelines create real financial pressure for practices — especially when documentation gaps drive the denial rather than inappropriate care.
MedHeave helps healthcare providers strengthen their revenue cycle by connecting clinical documentation to billing and authorization workflows.
- Revenue recovery for improperly denied claims
- Denial pattern analysis tied to payer-specific criteria
- Documentation improvement support for UR-related claims
- Prior authorization management across medical and behavioral health services
Contact MedHeave to see how your practice can reduce criteria-related denials and protect revenue.
Frequently asked questions
Here are some commonly asked questions about MCG guidelines:
MCG guidelines are proprietary, evidence-based clinical criteria used by healthcare organizations to evaluate medical necessity, level of care, admission status, continued stay, discharge readiness, and care transitions. Developed by MCG Health (a subsidiary of Hearst Health), the guidelines draw from systematic review of peer-reviewed medical literature and are updated annually. Payers, hospitals, and government agencies use MCG guidelines during utilization review to assess whether a requested service or care setting is clinically supported by the documented medical record.
In utilization review, MCG refers to MCG Health’s evidence-based care guidelines, originally known as Milliman Care Guidelines. The acronym is most commonly associated with the clinical criteria product used by utilization review nurses, case managers, payer review teams, and physician advisors to evaluate medical necessity during admission review, prior authorization, concurrent review, and discharge planning. MCG can mean other things in other healthcare contexts, but in UR and care management conversations, it almost always refers to MCG Health’s clinical decision-support guidelines.
MCG (Hearst Health) and InterQual (Optum) are both proprietary, evidence-based clinical criteria tools used in utilization management. MCG is often described as more oriented toward care pathways, recovery expectations, and goal length of stay benchmarks. InterQual is often described as more granular in its clinical element matching. The actual difference in daily practice usually depends on how a specific payer or health system has implemented and configured the tool rather than any inherent superiority of one product over the other.
Full MCG criteria are proprietary and typically accessed through licensed platforms, employer systems, or payer portals. Public pages on the MCG Health website explain the product and its care categories, but they do not provide the complete proprietary criteria. Providers searching for “MCG guidelines PDF” should be cautious because downloaded criteria from unofficial sources may be outdated, incomplete, or mismatched to the payer’s current edition. Payers implement updated MCG versions on their own schedules, so criteria versions can vary by health plan.
MCG guidelines may be one factor in a utilization review decision, but denials depend on payer policy, benefit coverage, clinical documentation, medical necessity evaluation, and applicable Medicare, Medicaid, or state rules. The guidelines support the review process rather than independently denying care. If a case does not meet MCG criteria at first-level screening, the case typically moves to physician review, a request for additional documentation, peer-to-peer discussion, or a formal appeal, depending on the payer’s procedures and regulatory requirements.
