CPT code 99225 – Subsequent observation care

Key takeaways

CPT Code 99225 is a deleted subsequent observation care code. The AMA removed it from the CPT code set effective January 1, 2023.

The code applied to observation patients responding inadequately to therapy or with a minor complication, typically with about 25 minutes of physician time.

Since 2023, subsequent observation care is billed with the unified inpatient/observation codes: 99231 (low), 99232 (moderate) or 99233 (high complexity).

Time-based 99232 starts at 35 minutes, so a visit that once met 99225 at about 25 minutes needs moderate MDM documented instead.

Pabau’s claims management software sends claims through Claim.MD, where clearinghouse checks can stop a deleted code like 99225 before it reaches the payer.

CPT Code 99225: Official descriptor and service category

CPT Code 99225 is a deleted evaluation and management code for subsequent observation care, per day. It sat in the Hospital Observation Services range (99217-99226) of the AMA’s CPT code set until January 1, 2023.

The official descriptor required at least two of these three key components:

• An expanded problem focused interval history.
• An expanded problem focused examination.
• Medical decision making of moderate complexity.

Counseling or care coordination was provided as the patient’s problems and the family’s needs required. Usually, the patient was responding inadequately to therapy or had developed a minor complication. Typically, 25 minutes were spent at the bedside and on the patient’s hospital floor or unit.

Coders applied 99225 on the middle days of an observation stay. Those fell after initial observation care (99218-99220) and before the discharge day (99217). It was the middle tier of the series, above 99224 (stable, low complexity) and below 99226 (unstable, high complexity).

Is CPT Code 99225 still active?

No, CPT Code 99225 is not active. The AMA deleted it effective January 1, 2023, in an E/M restructuring that retired the separate observation code series. That series ran from 99217-99220 for initial care to 99224-99226 for subsequent care. Any claim with 99225 for a date of service on or after that date will be rejected.

Claims for dates of service before January 1, 2023, remain valid under standard CMS policy for deleted codes. If a Medicare Administrative Contractor (MAC) or commercial payer audits 2022 or earlier, 99225 is still the right code for those dates. Check late-claim rules with your MAC, because policies vary by contractor.

The AMA retired the initial observation codes (99218, 99219, 99220) and the observation discharge code (99217) at the same time.

The same-day admission and discharge codes (99234-99236) stayed, revised to cover inpatient and observation stays alike. The aim was to stop tracking a patient’s status purely for coding when the clinical work matched inpatient care.

What replaced CPT 99225? The new observation code structure

The 2023 AMA E/M restructuring replaced the 99224-99226 subsequent observation series with the unified subsequent care codes 99231, 99232 and 99233.

These apply whether the patient is formally admitted as an inpatient or placed in observation status. The level depends on medical decision making (MDM) complexity or total time spent.

The biggest operational change is that coders no longer pick codes by observation or inpatient status. The clinical work and MDM complexity drive code selection. A hospitalist seeing a patient on day two of observation who is responding inadequately to IV antibiotics now bills 99232, not 99225.

The crosswalk below shows where each deleted code went, and why the new time thresholds catch out coders used to 99225.

Observation care vs inpatient admission: Billing distinction

Observation status and inpatient admission are distinct administrative classifications, and the distinction carries significant financial consequences for patients under Medicare. Under Medicare Part B, a patient in observation is treated as an outpatient. They pay 20% coinsurance on each covered service and the full cost of any self-administered drugs.

An inpatient admission falls under Medicare Part A, which applies a single deductible and covers approved medications as part of the stay.

Before 2023, this distinction also drove code selection. Observation patients used the 99218-99226 series, and inpatients used the 99221-99233 series. That split is gone.

Post-2023, the unified 99221-99223 (initial) and 99231-99233 (subsequent) codes apply regardless of status. The status still matters for the patient’s bill; it no longer drives which E/M code the physician selects.

Documentation requirements for CPT 99225

For pre-2023 claims, CPT Code 99225 required two of three key components. Those were an expanded problem focused interval history, an expanded problem focused examination, and moderate-complexity medical decision making. Alternatively, coders could bill on time, with about 25 minutes at the bedside and on the patient’s floor or unit.

A complete 99225 note had to include these elements to withstand audit under standard AMA CPT guidelines:

• Interval history: a focused update since the previous observation day, capturing any change in symptoms, response to treatment, or new complaints.
• Physical examination: an expanded problem focused examination of the affected body area and related systems. A detailed examination supported 99226 instead.
• Medical necessity statement: explicit documentation that continued observation is warranted, explaining why the patient cannot be discharged or admitted.
• MDM documentation: data reviewed (labs, imaging, prior records), diagnoses considered, and management plan updates reflecting moderate complexity.
• Response to treatment note: a statement that the patient is “responding inadequately to therapy” or has “developed a minor complication.” This language sets the 99225 tier, so it must appear or be clearly implied in the narrative.
• Physician time attestation (if time-based): total time spent on the patient’s floor or unit, including time outside the room reviewing results and coordinating care.
• Treating physician signature: a countersignature from the attending, not just a resident or mid-level provider, unless the payer has approved shared visit billing.

Ensuring medical billing compliance on observation notes requires building these elements into the EHR template so they are not omitted under time pressure. A missing medical necessity statement gets the claim denied, however thorough the rest of the note is.

How to bill for subsequent observation care: Step-by-step

For current claims (January 1, 2023, onward), billing subsequent observation care follows the unified inpatient/observation framework. The steps below apply directly and replace the old 99224-99226 workflow.

1. Confirm the service date and patient status. Verify whether this is day 1 (initial care, use 99221-99223), a middle day (subsequent care, use 99231-99233), or the discharge day (use 99238 or 99239).
2. Select the basis for code selection: MDM or time. Time-based billing counts all physician time on the date of service, including non-face-to-face work. MDM-based billing requires documentation of complexity across data, diagnosis, and risk domains.
3. Choose the correct level under the unified series. Low MDM or 25-34 minutes: 99231. Moderate MDM or 35-49 minutes: 99232. High MDM or 50 minutes or more: 99233.
4. Complete the note before submitting the claim. The claim must reflect documented complexity. A 99232 claim with a brief note documenting low-complexity MDM will not survive audit.
5. Route the claim through a clearinghouse. Submitting through a clearinghouse such as Claim.MD adds real-time eligibility checks and can catch deleted or invalid codes before the payer sees them. Pabau’s automated claims management software connects to Claim.MD and keeps the Send button disabled until required claim details are in place.
6. Monitor the remittance advice. If the claim comes back denied, review the Claim Adjustment Reason Code (CARC). It shows whether the issue is complexity, a deleted code, or a payer-specific Local Coverage Determination (LCD) restriction.

CPT 99225 vs adjacent codes: 99224, 99226, 99232 and 99233

Upcoding and downcoding errors in the subsequent observation series were common before 2023 and remain a risk in the unified series.

The table below maps the full pre- and post-2023 code families side by side, making the complexity thresholds explicit. A clean claim needs the level that matches both the documented MDM and the note’s clinical narrative.

Time is where coders moving from the old system trip up. The post-2023 99232 starts at 35 minutes, while the old 99225 typically involved about 25. A physician used to reaching 99225 with a shorter visit must document more time or meet moderate MDM explicitly to justify 99232.

Refer to the CMS Physician Fee Schedule lookup tool for current reimbursement values by code and locality.

Medicare reimbursement rate for CPT 99225

CPT Code 99225 is deleted, so no current Medicare Physician Fee Schedule (MPFS) rates apply. Historical rates for pre-2023 service dates varied by locality through the Geographic Practice Cost Index (GPCI) adjustments CMS applies to all E/M codes.

Facility and non-facility rates also differed. A patient in a hospital observation unit triggered the facility rate, and the non-facility rate applied elsewhere.

For historical rate lookups covering 2022 and earlier, use the FastRVU lookup tool filtered to the applicable fee schedule year. For current reimbursement on 99232, the functional replacement for 99225-level work, the CMS fee schedule search gives national rates. Your MAC then adjusts them using your locality’s GPCI values.

The work RVU for 99232 is 1.59 under the 2024 MPFS, up from 1.39 before the 2023 revaluation. Rates update annually, so verify against the applicable year’s published values.

Common reasons CPT 99225 claims were denied

Denial patterns for CPT Code 99225 followed consistent themes across payers. Understanding them remains relevant for retroactive audits and informs denial prevention on the current 99232 equivalent. Robust denial management workflows start with knowing which failure mode triggered each rejection.

• Missing medical necessity documentation. The note did not explicitly justify why the patient required continued observation rather than discharge or inpatient conversion. Reviewers look for a clear statement that discharge criteria are not yet met.
• Missing “responding inadequately” language. 99225 required that the patient be responding inadequately to therapy or have a minor complication. Notes that described a stable, improving patient but selected 99225 triggered downcoding or denial.
• Duplicate billing on same-day admission and discharge. When a patient was placed in observation and discharged on the same calendar day, only the combined same-day observation admission and discharge code applied. Billing a subsequent care code like 99225 alongside it created a duplicate.
• Using 99225 on post-2023 claims. Submitting a deleted code number on current-date claims results in an automatic denial. This remains a recurring billing error where charge capture templates were not updated after the January 1, 2023, code deletion.
• Status mismatch: inpatient billed as observation. A patient formally admitted as inpatient with a 99225 (observation-category code) created a status conflict. Payers cross-referenced the facility claim (UB-04) against the physician claim (CMS-1500) to catch these.
• Time documentation insufficient for time-based billing. When the physician chose time as the basis, the note had to clearly document total time, not just time at the bedside. Vague entries like “spent significant time” without a specific figure were denied.

Reviewing common denial codes in medical billing can help revenue cycle teams identify patterns across observation claims before they accumulate into write-offs. The medical claims clearinghouse layer catches many of these errors before the claim leaves the practice management system.

Payer-specific policies and LCD requirements

CMS sets the federal framework for observation billing, but Medicare Administrative Contractors issue Local Coverage Determinations that add jurisdiction-specific requirements.

MACs have differed on acceptable observation duration, required supporting diagnosis codes, and documentation detail for extended stays. A patient in a Noridian jurisdiction may face different audit triggers than one in a CGS jurisdiction for the same clinical presentation.

Commercial payers operate entirely outside the CMS framework. Many impose their own observation billing policies, prior authorization requirements, and time limits.

Some commercial contracts require notification within hours of a patient being placed in observation status; others require clinical review on day two. Check individual payer contracts and policy bulletins rather than assuming CMS rules apply.

Systematic monitoring of these policies is an underappreciated part of revenue cycle management that prevents observation-specific denials before they reach the claims stage.

The AAPC Codify CPT lookup indexes MAC and commercial payer policy articles alongside code descriptors. It’s a practical starting point when researching LCD requirements for a specific observation scenario.

How claims software keeps observation claims clean

Without a check at submission, a deleted code shows up only as a denial. An old charge capture template still lists 99225, the claim goes out, and the rejection arrives weeks later.

Pabau’s claims management software builds the claim from the invoice, with the patient, treatment and insurer details already attached. Validation checks keep the Send button disabled until required details are in place. Claims then go to payers through Claim.MD, with real-time eligibility checks and status tracking.

Your billing team spends less time on resubmissions and more on the documentation queries that decide the 99231-99233 level.

Keep deleted codes off your observation claims

Pabau’s claims management software, connected to Claim.MD, checks claim details before they go out and tracks every claim to payment. See how it works for hospital-based and multi-specialty practices.

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Conclusion

If your charge capture templates still list 99224-99226, retire them now and map each one to its unified replacement. That single update removes the denial that 99225 triggers automatically on any current-date claim.

The harder change is time. A visit that once reached 99225 at about 25 minutes won’t reach 99232 on time alone. Document moderate MDM in the observation note, or bill 99231 when the note supports only low complexity.

For pre-2023 audits, defend 99225 notes on the old key components, not the new MDM rules. Either way, the note has to show why the patient is still there and what the physician did about it.

Book a demo to see how Pabau checks observation claims before they reach the payer.

Continue your research

Coding a low-complexity follow-up day? CPT code 99231 covers the straightforward or low-MDM tier that replaced 99224.

Managing an unstable observation patient? CPT code 99233 explains the high-MDM tier that replaced 99226.

Frequently asked questions