X-Ray Machine Registration & State Inspections

Diagnostic X-ray machines are regulated by the FDA and the states — not by the NRC. The FDA sets federal performance standards on the equipment as manufactured; state radiation-control programs register and inspect the machines in clinical use; and the NRC governs only radioactive material, never radiation-producing machines. Understanding this three-way split is the difference between a facility that passes inspection and one that is surprised by a citation.¹⁶⁷⁸

Few regulatory topics generate as much confusion as who is responsible for an X-ray unit. Facilities that hold an NRC or Agreement State materials license for radiopharmaceuticals often assume the same agency oversees their CT and radiography rooms — it does not. X-ray machines occupy a distinct regulatory lane defined by federal equipment standards and state registration and inspection. This guide maps that lane, states the key numeric limits, and explains where mammography's federal survey mandate fits.

Introduction

A radiation-producing machine emits ionizing radiation only when energized and contains no radioactive material, which is precisely why it is regulated differently from a radioactive source. The legal authority, the responsible agency, and the compliance obligations all follow from that physical distinction.⁶⁷

Three separate authorities touch a diagnostic X-ray system across its life cycle:

1. The FDA regulates the design and manufacture of the equipment under the Electronic Product Radiation Control provisions of the Federal Food, Drug, and Cosmetic Act, through performance standards in 21 CFR Part 1020.¹²
2. The state radiation-control program regulates the possession, registration, and use of the machine once it is installed, and conducts periodic inspections — most states patterning their rules on a national model.⁸
3. The NRC (or an Agreement State materials program) does not regulate the machine at all; its jurisdiction is limited to byproduct, source, and special nuclear material.⁶⁷

This guide walks through each authority, the performance standards and their numeric limits, how state registration and inspection work, the mammography exception under MQSA, and where a qualified medical physicist fits. DRPS supports facilities with equipment testing, compliance documentation, and inspection readiness through its diagnostic radiography physics and accreditation support services across Florida, Maryland, Virginia, Washington DC, California, Nevada, Pennsylvania, New York, New Jersey, and Delaware.

Topic Explanation

Why machines and materials are regulated separately

The Atomic Energy Act gives the NRC authority over byproduct, source, and special nuclear material. An X-ray tube contains none of these — it is an electrical device that produces radiation only while high voltage is applied. When the machine is off, it is radiologically inert. That is the legal and physical reason the NRC has no role in X-ray regulation, and why an Agreement State's materials program is separate from its machine (X-ray) program, even when both sit inside the same state health department.⁶⁷

Instead, machine-produced radiation is addressed at two levels: the federal government regulates the product (the equipment), and the states regulate the practice (owning and using it). This mirrors how many electronic products are handled — the federal floor sets what may be manufactured and sold, while day-to-day oversight is local.

For facilities that also hold a materials license, the contrast with NRC oversight is instructive; see preparing for an NRC inspection for the materials side and how it differs from a state X-ray inspection.

The FDA layer: performance standards on the equipment

The FDA's Center for Devices and Radiological Health administers the Electronic Product Radiation Control program, originally enacted as the Radiation Control for Health and Safety Act of 1968 and now part of the Federal Food, Drug, and Cosmetic Act. Under this authority, the FDA prescribes performance standards that diagnostic X-ray equipment must meet as manufactured, codified in 21 CFR Part 1020: general diagnostic systems (1020.30), radiographic equipment (1020.31), fluoroscopic equipment (1020.32), and computed tomography (1020.33).¹²³⁴⁵

These are equipment standards, not clinical operating rules. They constrain the manufacturer and the assembler — for example, the person who installs a system must certify it and file an assembler's report (FDA Form 2579) with the purchaser and the state radiation-control agency within 15 days of assembly.² The standards define measurable ceilings — leakage, beam quality, output reproducibility, dose display — that a physicist can verify during acceptance testing.

The state layer: registration and inspection

Once a machine is in a facility, the state takes over. State radiation-control programs require registration of each radiation-producing machine and conduct periodic inspections. Because uniform federal use rules do not exist for X-ray machines, most states adopt the Conference of Radiation Control Program Directors (CRCPD) Suggested State Regulations for Control of Radiation, whose Part F addresses medical diagnostic and interventional X-ray and imaging systems. This model keeps state rules broadly consistent while leaving each state to set its own registration process, fees, and inspection cadence.⁸

Key Technical Principles

The three-agency jurisdiction map

The single most useful thing a compliance officer can internalize is who owns which question:

The mammography exception, discussed below, is the one place where the FDA reaches into machine use with a federal physicist-survey mandate.¹⁰

Key 21 CFR Part 1020 limits

The performance standards translate into specific numbers a physicist checks at acceptance and monitors over time. The most frequently cited limits are:

The historical leakage limit was expressed as 100 mR/h; the current air-kerma equivalent of 0.88 mGy/h reflects the CFR's move to SI dose quantities. The 88 mGy/min fluoroscopy ceiling likewise corresponds to the older 10 R/min figure, and 176 mGy/min to 20 R/min.²⁴ For a deeper treatment of the fluoroscopy limits and how they relate to displayed dose, see fluoroscopy air-kerma-rate limits and the ADRC.

Worked example: a fluoroscopy compliance check

Suppose a physicist measures an entrance-point exposure rate of 12 R/min on a fluoroscope during acceptance testing. The CFR uses the equivalence that 1 roentgen corresponds to about 8.8 mGy air kerma, so the measured rate converts as:

$$\dot{K}=\dot{X}\times 8.8\frac{\text{mGy}}{\text{R}}=12\frac{\text{R}}{\text{min}}\times 8.8\frac{\text{mGy}}{\text{R}}=105.6\frac{\text{mGy}}{\text{min}}$$

Comparing against the limits:

• Normal-operation ceiling = 88 mGy/min → 105.6 > 88 → exceeds the 21 CFR 1020.32 normal-operation limit.
• High-level control ceiling = 176 mGy/min → 105.6 < 176 → within the HLC ceiling.

So a reading of 105.6 mGy/min is a compliance failure for routine fluoroscopy and requires corrective action — it would only be permissible while the audible, continuously activated high-level control is engaged.⁴ This is exactly the kind of finding that separates a documented acceptance test from an assumption that "the vendor set it correctly."

Clinical Impact

Getting the regulatory framework right is not a paperwork exercise — it affects patient dose, staff safety, and a facility's ability to operate:

• Dose control. The 21 CFR 1020 limits are ceilings, not targets. A machine operating just under the leakage or fluoroscopy limit still delivers meaningful dose; acceptance testing and periodic physics evaluation confirm the equipment performs as designed and support optimization below the ceilings.
• Inspection outcomes. An unregistered machine, a missing assembler's report, or an out-of-tolerance output are common state-inspection findings. They can lead to citations, fines, or an order to stop using the unit until corrected.
• Continuity of service. For accredited modalities and for mammography, a lapsed physicist survey or accreditation can halt billing or force a facility to stop imaging. The regulatory calendar is therefore an operational calendar.
• Patient trust and liability. Documented compliance — registration, performance testing, QC records — is the evidence a facility relies on if a dose event or complaint is ever investigated.

Facilities pursuing accreditation should align their state compliance with accreditation physics requirements; see ACR accreditation physics requirements.

Practical Optimization Tips

A defensible X-ray compliance program tends to follow the same habits.

1. Build and maintain a machine inventory

Keep a current inventory of every radiation-producing machine: manufacturer, model, serial number, room, installation date, and registration status. State inspectors work from this list, and gaps between the physical inventory and the state registration are a frequent finding.

2. File and keep the assembler's report

When a machine is installed or relocated, confirm the assembler filed the FDA Form 2579 report of assembly with the purchaser and the state agency, and keep a copy. This is easy to overlook during a busy installation and hard to reconstruct later.²

3. Register before first clinical use

Register each machine with the state radiation-control program on the state's required timeline, before clinical use where the state requires it. Because registration processes and deadlines vary by state, verify the specific requirement for your jurisdiction rather than assuming.

4. Schedule acceptance testing and periodic physics evaluations

Have a qualified medical physicist perform acceptance testing on new or relocated equipment and periodic performance evaluations thereafter, verifying the 21 CFR 1020 parameters and any state- or accreditor-required tests. Track the results and the recommended corrective actions. DRPS provides this through diagnostic radiography physics, CT physics testing, and fluoroscopy physics testing.

5. Treat the inspection calendar as an operational calendar

Map every recurring obligation — state inspection windows, mammography annual survey, accreditation renewals — onto one calendar with owners and lead times. The most damaging findings are usually missed deadlines, not failed measurements.

6. Keep the documentation an inspector will ask for

Maintain registration certificates, assembler reports, physics survey reports, QC logs, operator credentials, and shielding documentation in one accessible place. See common radiation safety violations and how to avoid them for the findings that recur most often.

Common pitfalls to avoid

• Assuming the NRC or a materials license covers the X-ray machines. It does not; machines are a separate state program.
• Skipping the assembler's report. A missing Form 2579 is a citable gap.
• Confusing registration with compliance. Registration is necessary but not sufficient; performance standards, QC, and inspections still apply.
• Applying mammography's federal survey rule to all machines — or vice versa. MQSA is modality-specific; other modalities follow state and accreditor requirements.

Regulatory Considerations

The regulatory obligations for an X-ray program stack: a federal equipment floor (FDA), a state use-and-inspection layer, and, for mammography, an additional federal quality mandate (MQSA). Each layer has to be satisfied independently.¹⁸¹⁰

Federal equipment standards (FDA). Equipment must comply with 21 CFR Part 1020 as manufactured, and assemblers must certify and report installation. These standards define the leakage, fluoroscopy, reproducibility, beam-quality, and CT dose-reporting requirements listed above.²³⁴⁵

State registration and inspection. Under the CRCPD-modeled state programs, facilities register machines and undergo periodic inspection. In Florida, the Department of Health, Bureau of Radiation Control administers Chapter 64E-5, Part V, "X-Rays in the Healing Arts," including machine registration and mammography-specific requirements; inspection intervals vary by machine type, tending to be more frequent for higher-risk systems such as mammography and therapy units and less frequent for lower-risk units such as dental. Facilities should confirm their own state's registration timeline and inspection cadence.⁹ For Florida specifics, see Florida radiation safety requirements for imaging centers.

The mammography exception (MQSA). Mammography is the one modality where the FDA mandates a federal quality program that reaches into use, not just manufacture. Under the Mammography Quality Standards Act and its regulations at 21 CFR Part 900, a facility must be accredited and certified, must undergo annual inspection, and must have a qualified medical physicist perform an annual survey; certificates are valid for three years. This federal floor overlaps and reinforces the state layer.¹⁰ See mammography quality control and MQSA and the mammography physics and MQSA service.

Jurisdiction across DRPS service areas. For radioactive material, Florida, Maryland, Virginia, California, Nevada, Pennsylvania, New York, and New Jersey are NRC Agreement States, while Washington, DC and Delaware are regulated directly by the NRC. For X-ray machines, however, all of these states run their own radiation-machine registration and inspection programs regardless of Agreement State status — because machine regulation is a state function independent of the NRC materials framework. A facility must engage the correct program for each: the state X-ray program for machines, and the NRC or Agreement State materials program for radionuclides.⁶⁷

Frequently Asked Questions (FAQs)

Does the NRC regulate X-ray machines?

No. The NRC and Agreement States regulate byproduct, source, and special nuclear material — radioactive material such as I-131 or Tc-99m. X-ray machines and accelerators produce radiation only when powered and contain no radioactive material, so they are regulated by the states, while the FDA sets federal performance standards on the equipment as manufactured.

What does the FDA regulate about diagnostic X-ray equipment?

The FDA's Center for Devices and Radiological Health sets federal performance standards for X-ray equipment under 21 CFR Part 1020, covering diagnostic systems generally (1020.30), radiographic equipment (1020.31), fluoroscopic equipment (1020.32), and CT (1020.33). These standards apply to how the equipment is manufactured and must be met before it is sold, and assemblers must file a report of assembly.

Who inspects an X-ray machine after it is installed?

State radiation-control programs register radiation-producing machines and inspect them periodically. Most states model their rules on the CRCPD Suggested State Regulations. In Florida, this is the Department of Health, Bureau of Radiation Control, under Chapter 64E-5, Part V. Inspection intervals vary by machine type, from roughly annual for higher-risk systems to several years for lower-risk units.

What are the leakage and fluoroscopy dose limits in 21 CFR 1020?

Leakage radiation from a diagnostic source assembly is limited to 0.88 mGy air kerma in one hour at 1 meter under 21 CFR 1020.30. Fluoroscopic entrance air-kerma rate is limited to 88 mGy/min in normal operation, or 176 mGy/min when the high-level control is engaged, under 21 CFR 1020.32.

Is a medical physicist survey required by law for all X-ray machines?

No universal federal annual physicist survey exists for all X-ray machines. The clear exception is mammography: under MQSA (21 CFR Part 900), a qualified medical physicist must perform an annual survey and the facility undergoes annual inspection and 3-year certification. Many states and accreditation programs also require physicist evaluations for CT, fluoroscopy, and radiography, but the requirement comes from the state or the accreditor, not a single federal rule.

Does registering an X-ray machine make a facility compliant?

Registration is only the first step. Facilities must also meet the applicable equipment performance standards, maintain shielding and radiation safety documentation, keep operator and QC records, and pass periodic state inspection. For mammography and for accredited modalities, additional survey and accreditation requirements apply on top of state registration.

Key Takeaways

• Three agencies, three roles. FDA regulates manufacture, states regulate use and inspection, and the NRC regulates only radioactive material — not X-ray machines.⁶⁷⁸
• 21 CFR Part 1020 sets the equipment floor. Leakage ≤ 0.88 mGy/h at 1 m, fluoroscopy ≤ 88 mGy/min (176 with HLC), reproducibility CoV ≤ 0.05, HVL ≥ 3.6 mm Al at 100 kVp, and CT dose reporting are the headline limits.²³⁴⁵
• Registration is not compliance. You must also meet performance standards, keep documentation, and pass periodic state inspection.⁸⁹
• Mammography is the federal exception. MQSA requires an annual medical physicist survey, annual inspection, and 3-year certification under 21 CFR Part 900.¹⁰
• A physicist test catches what a limit hides. A fluoroscope reading 105.6 mGy/min sits under the HLC ceiling but violates the normal-operation limit — only measurement reveals it.⁴
• State X-ray programs are independent of Agreement State status. Every state regulates its own machines regardless of who regulates its radioactive material.

Conclusion

The regulation of diagnostic X-ray machines is not complicated once the jurisdiction is clear: the FDA constrains the equipment, the state registers and inspects the practice, and the NRC stays out of the machine business entirely. The confusion — and most citations — arise when a facility assumes a single agency owns everything, or that registering a machine is the same as complying with the standards that govern it.

A qualified medical physicist ties the framework together in practice: verifying that new equipment meets 21 CFR 1020, confirming performance stays within limits over time, and producing the documentation that state inspectors and accreditors expect. Facilities that treat registration, performance testing, and the inspection calendar as one integrated program — rather than three disconnected chores — protect patients, protect staff, and avoid the operational disruption of a failed inspection.

How DRPS Can Help

Diagnostic Radiation Physics Services helps imaging facilities build and maintain compliant X-ray programs: acceptance testing and periodic performance evaluations against 21 CFR 1020, shielding and radiation safety documentation, machine inventory and registration support, mammography physics under MQSA, and inspection and accreditation readiness. This work is delivered through our diagnostic radiography physics, CT physics testing, fluoroscopy physics testing, mammography physics and MQSA, and accreditation support services.

DRPS supports facilities across our service locations, including Florida, Maryland, Virginia, Washington DC, California, Nevada, New York, Pennsylvania, New Jersey, and Delaware. To review your registration and inspection readiness, contact our team.

Related Resources

• Florida radiation safety requirements for imaging centers
• Common radiation safety violations and how to avoid them
• Preparing for an NRC inspection
• Mammography quality control and MQSA
• ACR accreditation physics requirements
• Fluoroscopy air-kerma-rate limits and the ADRC
• Diagnostic radiography physics services
• Mammography physics and MQSA
• Accreditation support

References

1. U.S. Food and Drug Administration. Summary of the Electronic Product Radiation Control Provisions of the Federal Food, Drug, and Cosmetic Act. fda.gov
2. U.S. Food and Drug Administration. 21 CFR 1020.30 — Diagnostic x-ray systems and their major components. ecfr.gov
3. U.S. Food and Drug Administration. 21 CFR 1020.31 — Radiographic equipment. ecfr.gov
4. U.S. Food and Drug Administration. 21 CFR 1020.32 — Fluoroscopic equipment. ecfr.gov
5. U.S. Food and Drug Administration. 21 CFR 1020.33 — Computed tomography (CT) equipment. ecfr.gov
6. U.S. Nuclear Regulatory Commission. Regulation of Radioactive Materials. nrc.gov
7. U.S. Nuclear Regulatory Commission. Backgrounder on Agreement States. nrc.gov
8. Conference of Radiation Control Program Directors. Suggested State Regulations for Control of Radiation — Part F: Medical Diagnostic and Interventional X-Ray and Imaging Systems. crcpd.org
9. Florida Department of Health, Bureau of Radiation Control. Chapter 64E-5, Florida Administrative Code — Part V, X-Rays in the Healing Arts. flrules.org
10. U.S. Food and Drug Administration. Mammography Quality Standards Act (MQSA); 21 CFR Part 900. ecfr.gov
11. American College of Radiology and American Association of Physicists in Medicine. ACR–AAPM Technical Standards for Diagnostic Medical Physics Performance Monitoring of Radiographic, Fluoroscopic, and CT Equipment. aapm.org
12. Balter S, Rosenstein M, Miller DL, Schueler B, Spelic D. Patient radiation dose audits for fluoroscopically guided interventional procedures. Med Phys. 2011;38(3):1611-1618. doi:10.1118/1.3557868. PubMed
13. Li X, Hirsch JA, Rehani MM, et al. Radiation exposure in non-coronary fluoroscopically guided interventional procedures: reference levels of air kerma at the reference point and air kerma area product. Br J Radiol. 2021;95(1130):20211108. doi:10.1259/bjr.20211108. PubMed