CPT code 99418: Prolonged E/M, inpatient or observation2026 Medicare rate & RVUs in Illinois
CPT 99418 identifies each additional 15 minutes of prolonged physician or qualified health professional time for inpatient or observation E/M.
CMS doesn’t publish an office rate for 99418 in Illinois.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
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On this page 9 sections
What 99418 covers
CPT 99418 is an add-on code for prolonged evaluation and management work by a physician or other qualified health professional in the hospital inpatient or observation setting. It represents additional time associated with an inpatient or observation E/M service, rather than a separate visit. Examples of base services in this family include initial hospital care, subsequent hospital care, and same-day admission and discharge services.
Medicare marks 99418 as not valid for Medicare and uses G0316 to report and pay for this service. For Medicare claims, report G0316 when its requirements are met, not 99418. Each unit of 99418 represents an additional 15 minutes. Documentation should support the prolonged time and its relationship to the underlying inpatient or observation E/M service.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Where 99418 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
| Payment locality | Office | Facility |
|---|---|---|
| Chicago, IL | Unavailable | Unavailable |
| East St. Louis, IL | Unavailable | Unavailable |
| Rest of Illinois | Unavailable | Unavailable |
| Suburban Chicago, IL | Unavailable | Unavailable |
How the 99418 rate is calculated
Each of 99418’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · 99418
RVUs × geographic indexes × conversion factor
Work0.81
0.81 RVUs× 1.000 GPCI
Practice expense0.18
0.18 RVUs× 1.000 GPCI
Malpractice0.05
0.05 RVUs× 1.000 GPCI
Adjusted RVUs
1.0400
Conversion factor
$33.4009
Medicare rate
$34.74
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for 99418
The CMS indicators that decide how 99418 is paid alongside other services.
CMS payment indicators · 99418
Prolonged E/M, inpatient or observation
| Rule | CMS value | What it means |
|---|---|---|
| Global period | ZZZ | Add-on code: falls within the primary procedure’s global period. |
| Multiple procedures | 9 | The concept doesn’t apply. |
| Bilateral (modifier 50) | 9 | The concept doesn’t apply. |
| Assistant at surgery (80/81/82/AS) | 9 | The concept doesn’t apply. |
| Co-surgeons (62) | 9 | The concept doesn’t apply. |
| Team surgery (66) | 9 | The concept doesn’t apply. |
| Professional/technical | 9 | The concept doesn’t apply. |
99418 compared with similar codes
Compare codes · National
4 codes, side by side
How to choose
- G0316Prolonged E/MInpatient or observation care
- G0316 is the code Medicare uses for prolonged inpatient or observation E/M service. Medicare marks 99418 as not valid.
- 99417Prolonged E/MOffice or outpatient
- 99417 applies to prolonged outpatient E/M; 99418 is for prolonged inpatient or observation E/M.
- 99415Prolonged staff careFirst hour, outpatient E/M
- 99415 describes prolonged clinical staff service, not prolonged physician or qualified health professional inpatient or observation E/M.
99418 billing questions
Can 99418 be reported to Medicare?
No. Medicare marks 99418 as not valid and uses G0316 to report and pay for this service.
How does 99418 differ from 99417?
99418 is for prolonged inpatient or observation E/M time. 99417 is the corresponding prolonged-service code associated with outpatient E/M.
Which services can 99418 accompany?
It is an add-on for qualifying inpatient or observation E/M services, including initial hospital care, subsequent hospital care, and same-day admission and discharge services.
What does one unit of 99418 represent?
One unit represents an additional 15 minutes. Medicare claims use G0316 instead.
What should the record support?
Document the physician’s or qualified health professional’s prolonged time and its connection to the underlying inpatient or observation E/M service.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
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