In the medical device industry, there are tons of abbreviations. And as a medical device professional in the US working with Quality Management Systems Regulations (QMSR), or 21 CFR Part 820 as it’s technically known, you can easily get lost in this acronym ocean!
Until recently, the most important (and most confusing) abbreviations to understand were: DHF, DMR, DHR. These three abbreviations have been commonly used by the FDA for decades in relation to record-keeping requirements for medical device quality regulation:
- DHF - Design History File
- DMR - Device Master Record
- DHR - Device History Record
Although these traditional terms were widely used under the former Quality System Regulation (QSR), the FDA amended 21 CFR Part 820 effective February 2, 2026, incorporating ISO 13485:2016 by reference under the new Quality Management System Regulation (QMRS).
While the structure of the regulation changed, core documentation and record-keeping requirements remain in place and must continue to be managed compliantly.
This post explains how the regulations have changed, and what that means for your company.
Don’t miss our QARA guide to medical device quality management systems to understand the bigger picture of quality management in this changing landscape.
DHF, DMR, DHR, QMSR, and other important terms you should know
In the context of QMSR, or 21 CFR Part 820, medical device manufacturers must maintain structured documentation demonstrating the safety, effectiveness, and quality of their devices.
Historically, US regulation referred to three core documentation files: the Design History File (DHF), Device Master Record (DMR), and Device History Record (DHR).
Under QMSR, the FDA has aligned its terminology more closely with ISO 13485:2016, resulting in the DHF concept now being aligned with the Design and Development File (DDF), and manufacturers also being required to maintain a Medical Device File (MDF).
Although the legacy CFR sections defining DMR and DHR were removed or reserved under QMSR, manufacturers must still maintain equivalent production specifications and production history records as required under ISO 13485 provisions incorporated by reference.
Although all these files sound similar, they serve different purposes and contain documentation generated at different stages of the medical device lifecycle. Together, they demonstrate compliance with FDA requirements and support market access in the United States.
DHF - Design History File (now known as DDF - Design and Development File
Under the former QSR framework (prior to February 2, 2026), manufacturers were required to maintain a Design History File (DHF) under 21 CFR 820.30. The DHF documented how a device was designed and developed to meet user needs and regulatory requirements.
Under QMSR, this concept is aligned with the Design and Development File (DDF) terminology used in ISO 13485.
The detailed DHF terminology previously contained in 21 CFR 820.30 is no longer explicitly defined in the CFR text.
Instead, ISO 13485 design and development documentation requirements apply. The DDF contains records demonstrating that a medical device has been designed and developed according to pre-approved design plans and regulatory requirements. This includes design inputs and outputs, design reviews, and more.
DMR - Device Master Record
The Device Master Record (DMR) can be considered an instruction manual for the compliant manufacturing of the medical device. A DMR had to contain or refer to the information that was required to build the device, including specifications, acceptance criteria, drawings, BOMs (Bill of Materials), and maintenance/servicing procedures.
DHR - Device History Record
The Device History Record (DHR) contains all documents to prove that the instruction manual has been followed while manufacturing the medical device. A DHR refers to the date of manufacturing, quantity, acceptance records of manufactured medical devices, and unique device identifiers (UDIs) or any other unique device labels.
Although the specific DHR section (former §820.184) is no longer structured the same way in the amended regulation, production and traceability records equivalent to the former DHR remain required under ISO 13485 provisions incorporated by reference.
MDF - Medical Device File
The Medical Device File (MDF), introduced to align with ISO 13485:2016, contains documentation that demonstrates device conformity to applicable regulatory requirements. This file includes specifications such as labeling, product specs, intended use, and risk management.
International Quality Management System (QMS) for medical devices ISO 13485:2016
ISO 13485:2016 is an international standard that specifies requirements for a QMS for medical devices. The FDA wanted to align its requirements for medical devices with these standards, which is the reason for the recent regulatory changes to 21 CFR Part 820.
The ISO 13485:2016 refers to a Design and Development File (DDF) and a Medical Device File (MDF), which must contain records similar to those housed in the DHF, DHR, and DMR.
QSR and QMSR
21 CFR Part 820 used to be called Quality Systems Regulations (QSR) until New Year’s Eve 2024, when the FDA announced changes to the regulations and gave them a new name: Quality Management Systems Regulations (QMSR).
The new QMSR is much more aligned with international standards, ISO 13485:2016, and uses updated terminology rather than the traditional DHF, DMR, and DHR terms. But that doesn’t mean the requirements are vastly different. Even though QMSR doesn’t refer to the DHF, DMR, DHR files, the record-keeping requirements aren’t actually changing a great deal.
The difference between DHF, DMR, DHR and DDF
Even though the DDF, DMR, DHF, and DHR abbreviations sound very similar and confusing at first, here is a quick trick so you will never confuse them again:
Scilife Tip:
Focus on the function of the document rather than just the letters.
File (DDF, MDF) = structured technical documentation that defines or demonstrates compliance.
Record (DMR, DHR) = manufacturing-related documentation, including production specifications (DMR) and production evidence (DHR).
- The Design History File (DHF) was the former term used under QSR and is now aligned with the Design and Development File (DDF) under QMSR.
- The Design and Development File (DDF) shows that the device was designed and developed according to approved plans and regulatory requirements, including design inputs, outputs, and reviews.
- The Device Master Record (DMR) defines how the device must be manufactured, including specifications, processes, and acceptance criteria.
- The Device History Record (DHR) provides evidence that each device or batch was manufactured according to the DMR.
- The Medical Device File (MDF) demonstrates that the device conforms to applicable regulatory requirements, including specifications, labeling, intended use, and risk management documentation.
Here’s the documentation that DDF, DHF, DMR, and DHR for medical devices include:
Design and Development File (DDF)
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Design and development plans
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User needs and intended use
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Design inputs
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Design outputs
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Design review records
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Verification and validation (V&V) plans and results
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Risk management documentation
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Design changes and change control records
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Design transfer documentation
Design History File (DHF) is now considered a legacy term under QSR, containing documentation similar to what is now included in the Design and Development File (DDF).
Device Master Record (DMR)
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Design specifications, such as drawings, composition, formulation, component specs, and software specs
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BOMs (Bill of Materials)
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Production processes
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Equipment specifications
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Packaging and labeling specifications
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Quality assurance procedures and specifications
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Installation, maintenance, and servicing procedures
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Acceptance criteria
Device History Record (DHR)
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Acceptance records demonstrating compliance with the DMR
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Product and component IDs
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Material lots and serial number
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Production records
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Non-conformance reports
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Date(s) of manufacture
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Quantity manufactured
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Quantity released
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Primary identification labeling for each unit
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Unique device identifier (UDI) or universal product code (UPC), plus any other device identification(s) and control number(s)
The difference between DHF and DDF
Under the former QSR framework, the Design History File (DHF) enabled auditors to evaluate compliance with FDA design control requirements. It contained documentation demonstrating that the device was designed and developed according to approved plans, including records of design inputs, outputs, reviews, verification, validation, and design changes.
Under ISO 13485:2016, and now aligned under QMSR, this concept is referred to as the Design and Development File (DDF). The documentation requirements are largely similar, with updated terminology to reflect international harmonization.
The difference between DMR and MDF
As stated, the Device Master Record (DMR) defines how a medical device must be manufactured. It contains the specifications, processes, materials, quality assurance procedures, packaging, labeling, and other instructions necessary to consistently build the device according to approved requirements.
Under 21 CFR 820.181, manufacturers must establish and maintain a DMR for each type of device.
ISO 13485:2016 requires manufacturers to maintain a Medical Device File (MDF). The MDF contains documentation demonstrating conformity of the device to applicable regulatory requirements. While it may include or reference manufacturing information, it is broader in scope than the DMR and also includes product specifications, labeling, intended use, and other technical documentation.
Under QMSR, FDA requirements have been aligned more closely with ISO 13485 terminology, but manufacturing documentation requirements such as the DMR remain in place.
Quality Management System Regulation (QMSR) update: What happened to the DMR, DHF, DHR?
On New Year's Eve 2024, the FDA issued a final rule that 21 CFR Part 820 was changing, along with its name, from Quality System Regulation (QSR) to Quality Management System Regulation (QMSR).
These changes were made so that quality management regulations for medical devices in the United States are better aligned with the international standard ISO 13485:2016, which uses different terminology, such as Design and Development File (DDF) and Medical Device File (MDF), rather than the traditional DHF, DMR, and DHR terms. The rule became effective on February 2, 2026.
The Medical Device File (MDF)
The QMSR has moved away from the traditional terms: DHF, DHR, DMR, which were used in the previous QSR regulation.
Instead, it has adopted the term “Medical Device File” (MDF), in line with the international standard ISO 13485:2016. Under QMSR, which became effective on February 2, 2026, manufacturers must maintain a Medical Device File (MDF) containing documentation that demonstrates conformity with applicable regulatory requirements.
The good news is that most of the record-keeping requirements for medical devices aren’t changing in any major way. Much of what was contained in the DHF, DMR, and DHR for medical devices will still need to be documented.
Scilife Tip:
Just because the changes to record-keeping requirements aren’t major doesn’t mean that medical device companies can waste time getting up to speed. You must prepare your QMS and devices now, or risk noncompliance with QMSR.
But don’t panic! The FDA consistently points out that the requirements for QMSR are really very similar to the international requirements for ISO 13485:2016, which any medical device company that is operating internationally would already be following.
In fact, the FDA expects that by aligning 21 CFR Part 820 with ISO 13485:2016, a lot of “redundant effort” that some manufacturers make in complying with both US and international standards will be saved. Which can only be a good thing!
Managing DHF, DMR, DHR: Best practices for quality management record-keeping for medical devices
Although QMSR aligns certain terminology with ISO 13485 (including the use of the DDF and MDF), core documentation requirements such as the DMR and DHR remain in place. Record-keeping best practices for medical device quality management, therefore, remain largely unchanged.
Here are some best practices to follow:
Establish a robust QMS
Generally, you should ensure that your QMS provides a robust framework for managing all aspects of the medical device lifecycle, from design through to approval and quality control. Using a digital QMS can improve traceability and automate workflows, helping to ensure compliance and increase efficiency.- Centralized system: Create a centralized repository to help organize documents, including different versions (draft, review, or approved) and ensure proper version control and accessibility control
- Robust document control procedures: Outline how documents are created, reviewed, and approved
- Secure access controls: It’s not necessary for everyone to have access to all files. You need to define who can access, edit, and approve documents depending on their roles and responsibilities
- Formal change management: Implement a formal change management process so that any changes to the design, manufacture, testing, or record-keeping procedures can be properly managed
- Educate personnel: Personnel should receive ongoing, documented training related to their specific roles and responsibilities in relation to QMSR record-keeping, at all stages of the medical device life cycle
- Conduct regular audits: Don’t get caught off guard by the FDA! Conduct your own internal audits to ensure compliance with QMSR record-keeping requirements
During device design stages (historically managed through the DHF and now aligned with the DDF)
When developing medical devices, first comes the design stage. Records should be kept that keep together all the information on how the device was first designed, improved, and perfected.
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Start early: This ensures completeness of records and compliance
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Rigorous record keeping: Document every decision, activity, or approval related to the design and development of the device
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Prioritize traceability: Well-maintained records of the device design stage show clear traceability from user needs to design inputs and outputs
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Support continuous improvement: Devices are often improved, and the design files should make it as easy as possible for improvements and inform any future efforts
Standardizing production instructions (currently relevant to the DMR)
You’ve perfected the medical device design, and now you need to record the “recipe” so that each time a device is made, it’s produced consistently, according to design specifications.
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Record all production instructions and specifications: Records should contain all relevant manufacturing information
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Version control: All documents should have clear version numbers, dates, and authorship information
Ensuring batch production quality and traceability (currently relevant to managing the DHR)
Congratulations, your device is on the market! Now you need to keep records about the batches that you manufacture, including unique device identifiers that can be cross-referenced back to the source.
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Enable real-time updates: Record manufacturing and quality control activities as they occur, continuously, to ensure completeness.
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Prioritize traceability (again!): At this stage, traceability refers to materials, components, and manufacturing processes used to manufacture each batch of your devices.
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Prompt correction: Any problems in manufacturing that result in quality issues or deviations from the correct specifications or procedures should be identified and corrected efficiently, with documentation to show how they were resolved
Your roadmap to bringing a medical device to market without delays or compliance issues.
How can QMSR, DHF, DMR, DHR software help?
Our team at Scilife can help you prepare for the new rules outlined in QMSR, and get your current DHFs, DMRs, DHRs, and MDFs in order. We also provide a DHF, DMR, DHR software (our document management system) for maintaining, updating, and synchronizing your complete documentation.
The FDA requires manufacturers to maintain controlled, current versions of all design and production documentation consistent with QMSR and ISO 13485 requirements. To meet this requirement, you need an organized, accessible, and secure place to house these documents.
Choosing the right digital DHF, DMR, DHR software is crucial for easy document and version control. Consider a fully customizable platform so that you can revise and synchronize it to meet your needs.
With the right QMS software, you can fully digitize the record-keeping of the design and production of your medical devices and keep your documents audit-ready, with little to no additional effort. This will not only save you money and time but also provide peace of mind while you focus on advancing your device throughout its lifecycle.
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Consider these crucial features when choosing a document management system:
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Creating projects
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Creating document templates and getting approval for the templates
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Defining the contents of critical files at the beginning of each project
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Populating documents with approved content automatically
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Providing a version history for each document
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Having the latest approved files (MDFs, DMRs, and DHRs) collated and available to auditors
Conclusion
So, what is the best way to future-proof your medical device quality management documentation?
It starts with a robust (preferably digital) QMS. It continues with team awareness of what U.S. regulations require and how they have evolved under QMSR to align with ISO 13485 terminology, and it is backed by rigorous, formal record-keeping practices that demonstrate how your medical device was designed, validated, and manufactured to a consistent standard.
Discover how our medical device QMS can help keep your medical device documentation seamlessly connected and under control!
