CPT Code 00322: Anesthesia for Needle Biopsy of the Thyroid – Complete Billing & Coding Guide

CPT code 00322 describes anesthesia services administered during a needle biopsy of the thyroid gland. Formally classified under the AMA CPT category “Anesthesia for Procedures on the Neck,” this code carries 3 base units and is used exclusively when the surgical procedure performed is a percutaneous needle biopsy of the thyroid — not a thyroidectomy, not a thyroid exploration, and not a general neck procedure. Billing teams and anesthesia coders who conflate 00322 with its neighbor code 00320 regularly leave reimbursement on the table or expose claims to audit scrutiny, because the two codes carry meaningfully different base unit values and apply to different clinical scenarios.

What Does CPT Code 00322 Mean?

CPT 00322 is a time-based anesthesia code within the range 00100–01999, covering anesthesia for needle biopsy of the thyroid gland. The full AMA descriptor reads: Anesthesia for all procedures on the esophagus, thyroid, larynx, trachea and lymphatic system of neck; needle biopsy of thyroid.

Key attributes of this code at a glance:

• Code category: Anesthesia for Procedures on the Neck
• Base units assigned by CMS/ASA: 3
• Billable provider types: Anesthesiologists (MD/DO), CRNAs, Anesthesiologist Assistants (AAs)
• Applicable setting: Hospital, ambulatory surgery center (ASC), office-based
• Billing method: Time-based (base units + time units × conversion factor)
• MIPS eligible: Yes — added to MIPS program on January 1, 1990; descriptor unchanged since
• Age restriction: None specified (compare to 00326, which is restricted to patients under 1 year of age)

What Procedures Does CPT 00322 Cover?

CPT 00322 applies when an anesthesiologist or CRNA provides anesthesia services during a percutaneous needle biopsy of the thyroid gland. The surgical procedure code most commonly paired with it is CPT 60100 (Biopsy, thyroid, percutaneous core needle) or CPT 10005/10022 when fine needle aspiration (FNA) is performed with imaging guidance.

Clinical scenarios appropriately supported by 00322:

• Core needle biopsy of a thyroid nodule under ultrasound guidance requiring anesthesia due to patient anxiety, comorbidities, or procedural complexity
• Percutaneous thyroid biopsy in a patient whose clinical status (ASA physical status P3 or above) warrants monitored anesthesia care (MAC) or general anesthesia
• Thyroid biopsy performed in an OR or ASC setting where an anesthesia provider is formally part of the care team
• Needle biopsy of a substernal or deeply seated thyroid nodule requiring advanced positioning or airway management

What Does CPT 00322 Specifically Exclude?

Understanding the exclusions for 00322 is just as important as knowing its inclusions:

• Thyroidectomy procedures — partial or total thyroidectomy falls under CPT 00320, not 00322
• Tracheal or laryngeal procedures — use 00320 (age ≥1 year) or 00326 (age <1 year)
• Esophageal procedures — also reported under 00320
• Cervical spine or cord procedures — use CPT 00600, 00604, or 00670
• Neck vessel procedures — use CPT 00350 (major vessels, NOS) or 00352 (simple ligation)
• Integumentary/superficial neck procedures — use CPT 00300

When Is CPT 00322 the Right Code to Use?

The selection of 00322 over neighboring codes hinges on two factors: the specific surgical procedure being anesthetized, and the anatomical site involved. Follow this decision path before reporting the code:

1. Confirm the surgical procedure is a needle biopsy of the thyroid — not a thyroid resection, exploration, or other neck organ procedure. Review the operative note and the surgeon’s CPT claim.
2. Verify that a qualified anesthesia provider (anesthesiologist, CRNA, or AA) was present and providing reportable anesthesia services — not merely local anesthesia administered by the surgeon.
3. Confirm the patient’s age is 1 year or older — if the patient is under 12 months, evaluate whether 00326 (larynx/trachea, under 1 year) might be more appropriate depending on the neck procedure.
4. Confirm that anesthesia was medically necessary — payers, particularly MACs, are scrutinizing Monitored Anesthesia Care (MAC) for low-acuity thyroid biopsies in 2025. A documented clinical rationale (e.g., severe anxiety, bleeding risk, significant comorbidities) must be present in the anesthesia record.
5. Select the appropriate provider modifier (AA, QY, QK, QX, QZ, or AD) based on the care team model used.
6. Append the applicable physical status modifier (P1–P6) to stratify patient complexity.

How Does CPT 00322 Differ From CPT 00320?

This is the most common misapplication in thyroid anesthesia billing. The two codes share the same parent category but have fundamentally different clinical triggers and base unit values.

In practice, billing teams in multi-specialty practices often ask whether a thyroid biopsy performed under ultrasound guidance in a procedure suite qualifies for 00322. The answer depends on whether a separate anesthesia provider was present and performing a formally reportable anesthesia service — local anesthesia applied by the proceduralist does not trigger a separate anesthesia code.

What Documentation Is Required to Support CPT 00322?

What Must the Anesthesia Provider Document in the Anesthesia Record?

The anesthesia record is the primary supporting document for CPT 00322 claims. Required elements include:

1. Anesthesia start time — the moment the anesthesiologist begins preparing the patient for induction (pre-induction monitoring, IV placement for anesthesia purposes, positioning)
2. Anesthesia end time — when the anesthesiologist is no longer personally in attendance, typically at transfer to PACU
3. Total anesthesia time in minutes — entered in the units field on the CMS-1500; payers convert minutes to time units (1 unit per 15 minutes or fraction thereof under CMS; some commercial payers require 1-minute increment reporting)
4. Physical status assessment — documented ASA physical status classification (P1–P6) with supporting rationale for P3 and above
5. Type of anesthesia administered — general, regional, MAC; if MAC is selected, clinical rationale must be documented
6. Anesthesiologist/CRNA identity and supervision model — supports the provider modifier selected on the claim
7. Intraoperative monitoring entries — vital signs, airway management interventions, fluid administration, any unusual events or complications
8. Pre-anesthesia evaluation — completed and documented prior to the procedure
9. Post-anesthesia note — documents patient status at time of transfer from anesthesia care

What Are the Documentation Standards for Facility vs. Non-Facility Settings?

How Does CPT 00322 Affect Medical Billing and Reimbursement?

Anesthesia billing for CPT 00322 does not follow the standard RBRVS fee schedule. Instead, it uses the standard anesthesia payment formula: (Base Units + Time Units) × Conversion Factor = Allowable Amount.

CPT 00322 Base Unit and Payment Formula Summary

Note: The 2025 national Medicare anesthesia conversion factor reflects updates per the American Relief Act, 2025. Always verify the geographically adjusted conversion factor applicable to your MAC jurisdiction via the CMS Anesthesiologists Center before calculating expected reimbursement.

Key payer considerations for CPT 00322:

• Medicare: Covered when medically necessary; MAC anesthesia for a low-acuity thyroid biopsy may face increased scrutiny from Medicare Administrative Contractors in 2025
• Commercial payers: Conversion factors vary widely — some plans pay $50–$80 per unit, which can significantly exceed Medicare rates
• Medicaid: Medicaid conversion factors are set by individual states; many state Medicaid programs use the prior year’s Medicare conversion factor as their benchmark

What Modifiers Are Commonly Used With CPT 00322?

Are There Any Prior Authorization, Coverage Restrictions, or LCD Requirements?

• MAC (Monitored Anesthesia Care) medical necessity: Per the CMS Medicare Claims Processing Manual, Chapter 12, Section 50, MAC must be medically necessary, not simply patient preference. For a low-complexity thyroid biopsy, the anesthesia record must document the specific clinical rationale.
• Local Coverage Determinations: Check with your MAC for any LCD specifically addressing anesthesia for thyroid biopsy procedures; some MACs have issued guidance under their monitored anesthesia care articles.
• Global period: CPT 00322 carries a 0-day global period — all anesthesia services rendered on the date of the procedure are bundled within the anesthesia time.
• No prior authorization is typically required under Medicare for anesthesia services, but commercial payers may require pre-authorization for MAC or general anesthesia in an ASC setting.

What CPT or HCPCS Codes Are Commonly Billed Alongside CPT 00322?

Which Code Combinations Trigger NCCI or CCI Edits?

Per the CMS NCCI Policy Manual, Chapter 2 (Anesthesia), the following bundling rules apply:

• 00322 cannot be billed alongside a separate E&M code by the same anesthesia provider on the same date — pre- and post-operative evaluation by the anesthesiologist is bundled into the anesthesia payment.
• Anesthesia codes (00100–01999) cannot be combined with each other when multiple procedures are performed in a single session — report only the code with the highest base unit value; time units reflect the combined duration.
• Modifier 59 is not applicable to anesthesia codes — do not append -59 to anesthesia CPT codes.

What Coding Errors Should You Avoid With CPT 00322?

Anesthesia billing errors for 00322 tend to cluster around a few recurring patterns. In audit reviews of anesthesia claims, the following mistakes appear most frequently:

1. Upcoding to 00320 — Reporting 6 base units when only 3 are appropriate because the procedure was a needle biopsy, not a thyroidectomy or other neck organ procedure. This is the single most audit-flagged error for this code family.
2. Reporting anesthesia time for non-anesthesia activities — Including positioning, patient prep by non-anesthesia staff, or surgeon’s case time in the reported anesthesia minutes inflates time units fraudulently.
3. Missing or incomplete anesthesia start/stop times — Claims without exact documented start and stop times in the anesthesia record are a direct audit trigger and cannot be substantiated on appeal.
4. Applying modifier 23 without adequate documentation — Modifier 23 (unusual anesthesia) may be appropriate when general anesthesia is required for a procedure typically done under local or MAC, but the anesthesia record must explain the clinical necessity in detail.
5. Billing an E&M code separately by the anesthesiologist — Pre-op anesthesia evaluation is bundled into the anesthesia payment and cannot be separately reported by the same rendering provider.
6. Using 00322 for thyroid procedures other than needle biopsy — Fine needle aspiration, core needle biopsy, and similar percutaneous procedures are appropriate. Open thyroid biopsy or thyroidectomy requires 00320.
7. Incorrect supervision modifier — Using modifier AA when the physician was medically directing (requiring QK or QY) creates potential fraud exposure and may trigger a post-payment audit.

What Do Auditors and RAC Reviewers Look for When Reviewing Claims With CPT 00322?

• Anesthesia records with vague or missing time entries — RAC auditors and MAC medical review staff will compare billed time units against OR logs and nursing records
• MAC without documented medical necessity — A note saying “patient preferred sedation” is insufficient; auditors look for clinical comorbidities, anxiety disorders, or procedural complexity justifying MAC
• Provider modifier inconsistencies — Claiming AA while the CRNA’s own record shows unsupervised performance, or vice versa
• Billing 00320 and 00322 on the same date for the same patient — These codes cannot be combined in a single anesthesia session
• High-volume outliers — Practices billing 00322 at much higher rates than regional peers may be selected for comparative billing analysis by the OIG or CMS

How Does CPT 00322 Relate to Other CPT Codes?

What Is the Correct Code Sequencing or Reporting Order When CPT 00322 Appears With Other Codes?

1. Report 00322 as the primary anesthesia code on the CMS-1500 (box 24D).
2. Enter total anesthesia time in minutes in the units field (box 24G) — do not calculate time units yourself; payers apply their own conversion formula.
3. Append the provider modifier first (AA, QY, QK, QX, QZ, or AD) in the first modifier position (box 24D).
4. Append the physical status modifier second (P1–P6) in the second modifier position.
5. Report qualifying circumstance codes (99100, 99140) as separate line items if applicable.
6. Do not report 00320 and 00322 together — report the highest base unit code only if multiple neck procedures are performed in a single anesthesia session.

Real-World Coding Scenario — How CPT 00322 Is Applied in Practice

Clinical encounter: A 58-year-old patient with hypothyroidism and a known 2.1 cm thyroid nodule presents to the ASC for ultrasound-guided percutaneous core needle biopsy of the thyroid. The patient has a documented history of severe anxiety disorder and a prior syncopal episode during an office-based procedure. The endocrinologist requests MAC for patient safety. The anesthesiologist begins pre-induction preparation at 8:14 AM; the biopsy is completed and the anesthesiologist transfers care to PACU at 9:02 AM — a total anesthesia time of 48 minutes (3 time units under the 15-minute rule). The patient is classified ASA P2.

Correct Code Application

• Anesthesia code: 00322-AA-P2
• Surgical code (surgeon’s claim): 60100 + 76942 (ultrasound guidance)
• Time reported: 48 minutes in the units field
• Reimbursement estimate (Medicare): (3 base + 3 time) × $20.44 ≈ $122.64
• MAC documented justification: Severe anxiety disorder + prior syncopal episode noted in pre-anesthesia evaluation — medically necessary

Common Mistake in This Scenario

• Incorrect code selection: 00320-AA-P2
• Why it fails: 00320 carries 6 base units vs. 3 for 00322 — while it appears to generate higher payment, it misrepresents the procedure type and constitutes upcoding. On audit, the payer will compare the anesthesia code against the surgeon’s submitted code (60100), immediately flag the mismatch, and recoup the payment with potential additional liability.
• Documentation error: Anesthesia record that notes only “started ~8:15, done ~9:00” without exact times — insufficient to support the 48-minute time claim.

Frequently Asked Questions About CPT Code 00322

Is CPT Code 00322 Still Valid for Use in 2025 and 2026?

CPT code 00322 remains a valid, actively billable anesthesia code with no changes to its AMA descriptor since it was established on January 1, 1990. The CMS anesthesia base units for 00322 were confirmed unchanged for CY 2025 per the CMS Anesthesiologists Center update released December 2024. Coders should verify annually with the CMS Physician Fee Schedule and their MAC’s anesthesia conversion factor updates.

How Many Base Units Does CPT 00322 Carry, and How Does That Affect Payment?

CPT 00322 carries 3 base units as assigned by both CMS and the American Society of Anesthesiologists (ASA) Relative Value Guide. These base units reflect the lower complexity of a needle biopsy relative to more extensive thyroid or neck organ procedures. The final payment is calculated by adding the 3 base units to the time units accrued during the procedure, then multiplying the total by the geographically adjusted anesthesia conversion factor for the provider’s MAC jurisdiction.

What Is the Difference Between CPT 00322 and CPT 00320?

CPT 00322 applies exclusively to needle biopsy of the thyroid gland and carries 3 base units, while CPT 00320 covers all other procedures on the esophagus, thyroid, larynx, trachea, and neck lymphatic system for patients aged 1 year and older, and carries 6 base units. Using 00320 for a thyroid needle biopsy is an upcoding error that directly contradicts the more specific descriptor of 00322 and exposes claims to payer recoupment.

Does CPT 00322 Require a Separate Anesthesia Provider to Bill?

Yes. CPT 00322 — like all anesthesia codes in the 00100–01999 range — may only be billed when a qualified anesthesia provider (anesthesiologist, CRNA, or anesthesiologist assistant) is separately attending the patient and providing reportable anesthesia services. If the surgeon administers local anesthesia or mild sedation personally, no anesthesia CPT code is separately reportable; modifier 47 would be appended to the surgical code by the surgeon instead.

Can CPT 00322 Be Billed With Monitored Anesthesia Care (MAC)?

CPT 00322 can be billed for MAC services, but payers — particularly Medicare — require documented clinical justification for MAC when it is used for a procedure that can often be performed under local anesthesia. The anesthesia record must contain a clinician-documented rationale, such as a documented anxiety disorder, significant comorbidities, prior adverse reactions to local anesthetics, or unusual procedural complexity. A claim supported only by patient preference for sedation is likely to be denied or recouped on audit.

What Physical Status Modifiers Should Be Used With CPT 00322?

Physical status modifiers P1 through P6 are appended to anesthesia codes to indicate the complexity of the patient’s health status. For CPT 00322, the modifier is selected based on the anesthesiologist’s pre-procedure assessment: P1 (normal healthy patient), P2 (mild systemic disease), P3 (severe systemic disease), and so on. Under CMS/Medicare policy, physical status modifiers are informational and do not change the reimbursement formula; however, some commercial payers apply additional unit values for P3 and above — verify with individual payer contracts.

Key Takeaways for Billing and Coding CPT 00322

• CPT 00322 has 3 base units — using 00320 (6 base units) for a thyroid needle biopsy is an upcoding error and a leading audit trigger in the neck anesthesia code family.
• The standard anesthesia payment formula applies: (3 base units + time units) × conversion factor — there is no separate facility/non-facility RVU split for anesthesia codes.
• Exact start and stop times are mandatory in the anesthesia record; vague time entries cannot be defended on audit and cannot support appeal.
• The required provider modifier (AA, QY, QK, QX, QZ, or AD) must appear in the first modifier position on the claim; the physical status modifier (P1–P6) belongs in the second position.
• MAC anesthesia for thyroid biopsy requires documented medical necessity — patient preference alone does not meet payer standards in 2025.
• CPT 00322 pairs with surgeon codes 60100 (core needle biopsy) or 10005/10022 (FNA); verifying the surgeon’s claim before submitting the anesthesia claim helps prevent mismatched code combinations.
• Pre- and post-operative anesthesia evaluations are bundled into the anesthesia payment and cannot be separately reported by the same anesthesia provider on the same date.

For the most current anesthesia conversion factors and base unit tables, consult the CMS Anesthesiologists Center and the AMA CPT code set reference annually — both are updated each calendar year.