CPT code 93793 – Anticoagulant management, warfarin (INR review)

Key takeaways

CPT code 93793 covers anticoagulant management for warfarin patients only, and each unit starts from a new home, office, or lab INR result.

A dose change is not required, but the note must show the result was interpreted, the patient was instructed, and the next test was planned.

Report 93793 once per day at most, and never on the same day as an E/M service, which already includes the INR work.

Patients on DOACs such as apixaban or rivaroxaban fall outside 93793, so their follow-up contacts go under an E/M code that fits the visit.

CPT 93792 is a separate service: face-to-face training that gets a patient or caregiver started on a home INR meter.

CPT code 93793 covers warfarin management after a new INR result

CPT code 93793 reports anticoagulant management for a patient taking warfarin. Under the American Medical Association descriptor, every contact must include four elements:

• Review and interpretation of a new home, office, or lab international normalized ratio (INR) test result
• Patient instructions
• Dosage adjustment, as needed
• Scheduling of additional tests, when performed

The new INR result is the trigger. It can come from the patient’s home meter, an in-office device, or an outside lab. Each unit of 93793 is tied to that result, whether the follow-up happens by phone or in the office.

The code took effect on January 1, 2018. That year, CPT deleted the older anticoagulant management codes 99363 and 99364 and opened a new Medicine subsection for home and outpatient INR monitoring. 93793 and its companion code, 93792, are the only two codes in it.

Who may bill: Physicians and other qualified health care professionals report 93793 for interpreting the result and setting the plan. That group includes nurse practitioners and physician assistants. Nurses or anticoagulation pharmacists often make the call and relay the instructions. When clinical staff handle that part, the billing provider directs the plan and must meet the payer’s supervision rules, including Medicare’s incident-to requirements.

What a 93793 contact includes, and what sits outside it

A contact qualifies only when all four descriptor elements are met, with dosing and test scheduling done as the result requires. The line between included and separate work is where most unbundling errors start.

Included in 93793:

• Review and interpretation of a new INR result from a home meter, an office device, or a lab
• Instructions to the patient on dosing and on symptoms to report
• A dose adjustment when the result calls for one, or a documented decision to keep the current dose
• Scheduling of the next INR test, when it is performed

Outside 93793:

• The INR test itself, reported as CPT 85610 when your in-office lab draws and processes the sample
• Training a patient or caregiver to use a home INR meter, which is CPT 93792
• Follow-up for patients on DOACs such as apixaban, rivaroxaban, dabigatran, or edoxaban, who have no INR to review
• INR review done during an E/M visit on the same date, which the E/M service already includes
• Time counted toward chronic care management (99487, 99489, 99490) or transitional care management (99495, 99496)

A dose change is not a requirement. A stable INR with a documented decision to continue the current dose still supports the code, as long as the result is new.

Report 93793 once per day at most, however many INR results you review that day. Don’t report it alongside telephone or online digital E/M codes for the same work. When you also bill 85610 on that date, check NCCI edits and your payer’s rules for your setting first.

What the 93793 note must show

The note for each contact should let a reviewer rebuild the service from the descriptor. Following medical billing compliance standards means each element below appears in the chart.

The interpretation is the element notes most often leave thin. A line such as “INR reviewed, patient called” records that someone saw the result. It does not record a decision, so state the decision even when the dose stays the same.

ICD-10 codes that support a 93793 claim

The diagnosis codes on a 93793 claim need to show why the patient takes warfarin and that the therapy is ongoing. These are the codes that most often support it.

Lead with the condition that requires anticoagulation, and add Z79.01 to show the therapy is current. A claim carrying Z79.01 alone says the patient takes an anticoagulant, but not why.

93793 or 93792: Which one fits?

CPT 93792 and 93793 entered CPT together in 2018, but they describe different work. 93792 trains a patient to test at home, while 93793 manages warfarin after a result comes in.

93792 carries no physician work RVU, because clinical staff usually deliver the training. CMS published both codes with payment status A, which means Medicare pays them separately. Check each commercial plan’s policy before billing either code.

93793 or 99211 for a nurse INR visit?

A nurse INR visit can look like a 99211 visit on the schedule. Since 2018, CPT routes warfarin INR management to 93793, so the visit’s purpose decides which code applies.

• Bill 93793 when: The contact exists to act on a new INR result for a warfarin patient. The note shows the interpretation, the instructions, and the next test plan. A nurse visit that only reviews the INR and adjusts the dose fits 93793 rather than 99211.
• Bill the E/M service alone when: The patient also has a separately identifiable E/M visit that day. The INR review is included in that visit, so 93793 comes off the claim. Modifier 25 does not change this for 93793.
• Bill 99211 when: A nurse visit has a different purpose, such as a blood pressure check, and no INR management takes place.

The decision path below runs those checks in order, from the drug the patient takes to what the note records.

What Medicare pays for CPT 93793

Medicare pays CPT code 93793 under the Physician Fee Schedule. The amount changes each year and varies by locality. Search 93793 in the CMS Physician Fee Schedule lookup tool for your current rate.

Key points for Medicare billing:

• A diagnosis that supports long-term warfarin therapy must establish medical necessity.
• Report one unit per day at most.
• Use the place of service where the work is furnished. ICD10monitor guidance says a phone contact about an outside lab result, made from the office under a supervising provider, keeps POS 11.
• Home INR monitoring has its own national coverage determination (NCD 190.11) and HCPCS G-codes, such as G0250 for physician review of home tests. Check the current CMS rules before choosing between those codes and 93793.

For commercial plans, run insurance eligibility verification when warfarin therapy starts. Confirm the plan covers 93793 and whether it adds its own rules.

Can you bill 93793 by phone?

Yes, a phone or video contact can support 93793, because the descriptor does not require a face-to-face visit. What it needs is a new INR result, its interpretation, and instructions to the patient.

• Telephone and online codes: Don’t add a telephone or online digital E/M code for the same work.
• Medicare telehealth: Rules have changed several times since 2020. Confirm 93793’s status on the current CMS telehealth services list before billing it with telehealth POS codes or modifiers.
• Commercial payers: Coverage for virtual contacts varies by plan, so check each payer’s telehealth policy.

The documentation requirements stay the same however the contact happens. The chart still needs the result, the decision, the instructions, and the next test.

Before you submit a 93793 claim

Run this check on every 93793 line before it leaves the practice. Each item maps to a denial in the table further down.

• The INR result is new, with its value, collection date, and source in the note.
• The note states the decision, even when the dose stays the same.
• No E/M service is billed for the same patient on the same date.
• The patient takes warfarin, not a DOAC.
• The claim lists the condition that drives anticoagulation, plus Z79.01.
• The line carries one unit, and no other 93793 sits on that date.
• The place of service matches where the work was furnished.

From there, each claim follows the same short path. The contact note supports a 93793 charge, which carries the date of service and diagnosis codes onto the claim. A claim scrub checks the fields before you submit, and the payer’s remittance shows whether the line paid or needs a fix.

Why 93793 claims get denied

Most 93793 denials trace back to a few coding and documentation errors. The table pairs each one with its usual CARC and the fix.

Track CARC denial codes at the code level, so patterns specific to 93793 surface quickly. Building clean claim requirements into the contact note costs less than correcting claims after a denial.

Does CPT 93793 apply to DOAC patients?

No, CPT 93793 applies only to patients taking warfarin. The descriptor names warfarin and requires a new INR result. Apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa), and edoxaban (Savaysa) are prescribed without routine INR monitoring, so their follow-up contacts don’t meet it.

Report a DOAC follow-up under an E/M code that fits the visit, based on medical decision making or time. Document the kidney and liver results you reviewed, adherence, and the dose decision, as you would for any E/M visit.

How claims management software keeps 93793 claims moving

A practice that manages warfarin patients sends a steady stream of small claims. Each one needs the right date, diagnosis codes, and place of service, and a single missed field can hold up payment.

Pabau, the practice management platform we build, pre-fills each claim from the patient record. The 93793 charge and the diagnosis codes on the patient’s problem list carry over. Claim validation flags missing or invalid details before the claim leaves Pabau.

In the US, claims go out electronically through Claim.MD, with eligibility checks, claim-status tracking, and payment reconciliation from remittance files. Pabau’s claims management for practices keeps those steps together, so your billers can follow each 93793 claim from charge to payment.

Send warfarin management claims straight from the patient record

Pabau pre-fills each 93793 claim from the patient record and submits it electronically through Claim.MD, with eligibility checks and claim-status tracking built in.

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Conclusion

CPT 93793 rewards a disciplined note more than clever coding. Each billable contact starts with a new INR result for a warfarin patient and ends with a stated decision and a next test. DOAC follow-up and INR review inside an E/M visit belong under other codes.

So build the contact note around the four descriptor elements, and run the pre-submission check on every line. Your team then codes each contact without chasing the clinician, and fewer claims come back for missing documentation.

Book a demo to see Pabau pre-fill, submit, and track your 93793 claims from the patient record.

Continue your research

Need to understand how clearinghouse submission works for 93793? Medical claims clearinghouse guide explains the electronic submission pathway from practice to payer.

Want to reduce denial rates across your billing team? Denial management in healthcare covers systematic approaches to tracking and resolving claim rejections.

Billing warfarin patients through a superbill workflow? Superbill documentation guide outlines how to structure superbills that support 93793 and companion code billing.

Training a Medicare patient on a home INR meter? HCPCS code G0248 covers the home INR monitoring demonstration and when Medicare pays for it.

New to the billing cycle behind each 93793 claim? What is medical billing walks through how a charge becomes a paid claim.

Frequently asked questions