CPT code 00938: Anesthesia for penile prosthesis insertion

Key Takeaways

CPT code 00938 describes anesthesia for procedures on male genitalia, specifically insertion of a penile prosthesis via the perineal approach.

The code carries 4.0 anesthesia base units, confirmed by both the VA Community Care fee schedule and the DOL OWCP anesthesia table.

Physical status modifiers (P1-P6), CRNA supervision modifiers (QK, QX, QY, QZ), and the monitored anesthesia care modifier AA must be appended correctly to avoid claim denials.

Bill 00938 alongside the surgical prosthesis code (usually 54405 for an inflatable device or 54400 for a semi-rigid one) and the matching HCPCS device code, so the anesthesia claim is not denied for a mismatched primary procedure.

Pabau’s claims management software helps anesthesia practices track modifier requirements, submit accurate claims, and reduce denial rates across procedures like CPT 00938.

The American Medical Association (AMA) maintains CPT code 00938 with the following full descriptor:

Anesthesia for procedures on male genitalia (including open urethral procedures); insertion of penile prosthesis (perineal approach)

CPT code 00938 falls within the male genitalia sub-range (00920-00938), which itself sits inside the broader perineum anesthesia range (00902-00952). The perineal approach distinguishes this code from transcrotal or suprapubic prosthesis techniques. Coders sometimes reach for a general “not otherwise specified” male genitalia code when the operative report specifies perineal access. That is a misassignment.

The procedure itself involves implanting an inflatable or semi-rigid penile prosthetic device to treat erectile dysfunction that has not responded to conservative therapy. General or regional anesthesia is standard given the procedural complexity and typical surgical duration of 60-120 minutes.

For anesthesia billing reference on an adjacent procedure, see CPT code 00922, which covers seminal vesicle procedures and occupies the code immediately adjacent to 00938’s sub-range.

Where 00938 sits in the CPT hierarchy

• Section: Anesthesia (00100-01999)
• Subsection: Anesthesia for procedures on the perineum (00902-00952)
• Sub-range: Anesthesia for procedures on male genitalia, including open urethral procedures (00920-00938)
• Code: 00938 (most specific code in the sub-range, perineal approach)

Because 00938 is the terminal code in the male genitalia sub-range, it has no child codes. When the operative report documents a perineal prosthesis insertion, 00938 is the correct and only choice within this subsection. Using 00920 (NOS) for a case that clearly qualifies for 00938 undercodes the service and may trigger a payer audit.

Anesthesia base units and reimbursement for CPT 00938

Anesthesia billing uses a time-and-base-unit formula rather than the relative value unit (RVU) model used for most CPT codes. The formula is:

Allowable = (Base Units + Time Units + Qualifying Circumstances Units) x Conversion Factor

CPT code 00938 carries 4.0 base units, confirmed by the VA Community Care fee schedule (Table H) and the Centers for Medicare and Medicaid Services (CMS) Physician Fee Schedule. Time units are calculated at one unit per 15 minutes of anesthesia time, starting from when the anesthesiologist first becomes responsible for the patient through handoff to post-anesthesia care.

Reimbursement amounts vary materially by payer, geography, and contract year. Do not apply a single national rate to all claims. For current Medicare allowables, use the FastRVU RVU lookup tool or query the CMS Physician Fee Schedule directly by locality.

Practices billing workers’ compensation cases should reference the Department of Labor’s Office of Workers’ Compensation Programs (OWCP) Table 2 geographic conversion factors alongside the 4.0 base unit value.

CMS anesthesia base units are set by CPT code, not by the RVU model. The 4.0 value for 00938 stays fixed, while your Medicare anesthesia base units payout moves with time units and the local conversion factor.

Coverage still turns on your Medicare Administrative Contractor (MAC) and any local or national coverage determinations (LCDs and NCDs). Confirm the payer’s policy before you submit.

Tracking these calculations across a high-volume anesthesia practice is where billing errors compound quickly. Claims management software that supports anesthesia-specific unit calculation can flag discrepancies before submission rather than after a denial.

Modifiers for CPT code 00938

Modifier selection is the single most common source of denials on anesthesia claims. CPT code 00938 requires at least one anesthesia modifier on every claim to indicate who provided the service and under what level of supervision.

Physical status modifiers (P1-P6)

Physical status modifiers reflect the patient’s pre-anesthetic condition under the American Society of Anesthesiologists (ASA) classification system. They are determined by the anesthesiologist based on clinical judgment and must be supported by the pre-anesthesia evaluation in the chart.

Patients undergoing penile prosthesis insertion often present with comorbid conditions (diabetes, cardiovascular disease, neurological injury) that warrant P3 status. Assigning P1 or P2 when the pre-anesthesia evaluation documents significant comorbidities is a documentation mismatch that payers flag on post-payment audit.

Pabau’s HIPAA compliance guide covers the documentation standards that keep anesthesia claims audit-ready.

Medical direction and CRNA supervision modifiers

When an anesthesiologist medically directs Certified Registered Nurse Anesthetists (CRNAs) or anesthesiologist assistants, specific Healthcare Common Procedure Coding System (HCPCS) modifiers must appear on the claim. The correct modifier depends on how many concurrent cases the physician is directing and the payer’s policy.

Medical direction (QK/QX/QY) pays at 50% of the AA rate for both the physician and CRNA claims. Medical supervision (AD) pays only 3 base units to the physician, regardless of actual case duration. Verify the distinction in your payer contracts before assuming the default Medicare rule applies.

CPT procedural modifiers: 22, 23, and 53

Beyond physical status and supervision, three CPT-level modifiers occasionally attach to 00938. Each one needs operative-note support, or the payer strips it on review:

• Modifier 22 (increased procedural services) — the anesthesia work substantially exceeded the norm for the case. Document exactly why.
• Modifier 23 (unusual anesthesia) — a procedure normally done under local or no anesthesia required general anesthesia.
• Modifier 53 (discontinued procedure) — the case was stopped after induction, and the record must reflect the discontinuation.

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Documentation requirements for CPT code 00938

CMS and commercial payers require a minimum set of documentation for any anesthesia claim to pass audit. CPT code 00938 is no exception. Missing any of the following elements is the most common reason clean claims become contested claims.

Pre-anesthesia evaluation

The pre-anesthesia evaluation must be completed and documented before the procedure. It should include:

• The patient’s medical history, current medications, and allergies
• A review of prior anesthesia records
• A physical examination
• ASA physical status classification with clinical justification
• The anesthetic plan

Patients presenting for penile prosthesis insertion frequently have multiple comorbidities. Document each one specifically rather than using a generic “medical history reviewed” notation.

For practices managing digital intake forms and pre-procedural assessments electronically, structured templates reduce the risk of missing a required documentation element. Pre-anesthesia checklists embedded in the patient record flag completion status before the patient reaches the OR.

Intraoperative anesthesia record

The intraoperative record must show:

• Start and stop times of anesthesia (not surgery start/stop)
• Anesthetic agents used and dosages
• Monitoring parameters at regular intervals (blood pressure, heart rate, oxygen saturation, end-tidal CO2)
• The name, credentials, and role of every anesthesia provider present
• Any intraoperative events or interventions

The distinction between anesthesia time and surgical time matters for billing. Payers audit start-and-stop time discrepancies against the surgical facility’s records. A five-minute gap between the anesthesiologist’s documented start time and the OR log’s documented incision time is expected. A 30-minute gap raises questions.

Post-anesthesia evaluation

CMS requires a post-anesthesia evaluation within 24-48 hours of the procedure for inpatient cases. For outpatient procedures like penile prosthesis insertion, the evaluation is typically completed before the patient is discharged. Document the patient’s recovery status, vital signs at handoff, and any post-operative concerns. This entry supports the anesthesia claim and provides legal protection in adverse event situations.

Automated billing workflows can trigger post-anesthesia documentation tasks at the appropriate interval so nothing falls through the cracks. Many practices also use clinical documentation software to standardize record-keeping across specialties.

Related codes in the perineum anesthesia range

Choosing CPT code 00938 requires confirming that no adjacent code more precisely describes the service. The 00902-00952 range covers all perineum anesthesia procedures, and several codes within the male genitalia sub-range (00920-00938) are frequently confused with 00938.

The most frequent coding error in this range is using 00920 (NOS, 3.0 base units) when the operative report clearly documents perineal prosthesis insertion (00938, 4.0 base units). This results in a one-base-unit undercharge on every affected claim.

For practices billing a mix of urological and other procedures, practice management software with built-in CPT reference tables can surface the correct code at the point of charge entry rather than relying on coder recall alone.

Verify adjacent codes using the AAPC Codify CPT lookup, which displays neighboring codes and their official long descriptors side by side. This is particularly useful for the 00920-00938 sub-range where similar procedure names create confusion.

Urology practices billing elsewhere in this anesthesia family can also cross-reference CPT code 00914, which covers TURP anesthesia under a similar base-unit structure.

For broader anesthesia billing context beyond the male genitalia sub-range, IVF CPT codes illustrate how anesthesia and procedure codes interact across reproductive specialties that frequently overlap with urological surgical planning. Men’s health practices that bill both penile prosthesis anesthesia and related urological services benefit from men’s health clinic software with billing capabilities tailored to this specialty mix.

The same base-units-plus-time approach applies throughout the wider Anesthesia section. CPT code 00474 and CPT code 00524 each carry their own base unit value, calculated the same way as 00938’s 4.0 units.

CPT code 01820 follows the same formula in an entirely different anesthesia subsection, which shows how consistent the base-unit-plus-time method stays across the whole Anesthesia range.

CPT code for penile prosthesis: Pairing 00938 with the surgical codes

CPT code 00938 covers only the anesthesia. The surgeon bills a separate CPT code for the prosthesis itself, and the device carries its own HCPCS code. Getting all three onto the claim is what keeps a penile prosthesis case clean.

• 54400 — insertion of a non-inflatable (semi-rigid or malleable) penile prosthesis.
• 54405 — insertion of a multi-component inflatable penile prosthesis. This is the CPT code for penile prosthesis insertion coders reach for most often.
• C1813 — HCPCS device code for an inflatable penile prosthesis.
• C2622 — HCPCS device code for a non-inflatable penile prosthesis.

A search for the CPT code for penile prosthesis usually returns the surgical code, most often 54405 for an inflatable device. The anesthesia team bills 00938 alongside it. Confirm that the surgeon’s operative code and the device HCPCS code match the prosthesis actually implanted before submitting, so the anesthesia claim is not denied for a mismatched primary procedure.

Sexual health and urology practices that bill this combination regularly can also use sexual health clinic software to keep the anesthesia and surgical codes aligned on every claim.

Conclusion

Anesthesia billing for urological procedures like penile prosthesis insertion is vulnerable to systematic coding errors, most of which trace back to three points: assigning an NOS code when a more specific code (CPT code 00938) applies, applying the wrong supervision modifier, and producing a documentation record that doesn’t support the physical status modifier used.

Pabau’s claims management tools support surgical and anesthesia practices in building cleaner submission workflows, tracking modifier requirements by payer, and cutting down on the documentation issues that turn clean claims into denials. To see how it fits your practice’s billing workflow, book a demo.

Continue your research

Need anesthesia coding guidance outside the perineum range? CPT Code 01480: Anesthesia for open lower leg, ankle, and foot procedures walks through base units and modifiers for a different anesthesia sub-range.

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