Medication administration record (MAR): what it contains and how to read one

A medication administration record, almost always shortened to MAR, is a grid. Each row is 1 active medication order. Each column is a date, and inside each day sit the scheduled times. When a nurse gives a dose, the nurse records it in the cell for that time: an initial and the actual time on paper, or a bar-code scan and an electronic signature on an eMAR. When a dose is not given, the cell should carry a code that says why.

The MAR sits between 2 other documents. Upstream is the order, written by a physician, nurse practitioner or other prescriber and verified by a pharmacist. Downstream is the patient's response, charted in vital signs, pain scores, glucose logs and nursing notes. The MAR is the hinge. It is where the plan becomes an act, and it is usually the first place anyone looks when a patient was harmed by a drug or by the absence of one.

Every setting that gives medications keeps some version of it. Hospitals, nursing homes, assisted living, home health, hospice, psychiatric units, jails and schools all use MARs, and many state forms for group homes and assisted living are simply blank MAR grids. The layout changes from place to place. The questions a reviewer asks do not.

MAR, eMAR and BCMA

MAR

Medication administration record. Paper or electronic, 1 row per order, 1 cell per scheduled dose.

eMAR

The electronic MAR inside the EHR. Orders flow in from the prescriber and pharmacy, so nobody transcribes them by hand.

BCMA

Bar-code medication administration. The nurse scans the patient's wristband and the drug's bar code; the eMAR checks the match before the dose is charted.

Scheduled dose

A dose due at a set time (09:00, 21:00). The cell exists before the dose is given.

PRN dose

"As needed." Given for a stated reason, such as pain 4 to 6, so the entry needs the reason and the result.

Held, refused, omitted

3 different things. Held is a clinical decision, refused is the patient's decision, omitted means the dose did not happen and nobody recorded a reason.

ADC

Automated dispensing cabinet. The locked cabinet on the unit that logs every removal by user and time. Its report is a separate record from the MAR.

Waste

The part of a controlled-substance dose that is discarded, usually recorded with a second person as witness.

A printed MAR looks crowded because it carries 7 kinds of information on 1 page. The mock sheet below marks each one. The layout is invented; every real facility's form differs, but the same 7 parts are on all of them.

Codes for doses that were not given

Every facility writes its own legend, usually printed at the foot of the paper MAR or in the eMAR's help text. The table shows the categories you will meet; the exact letters and numbers change from one form to the next, so always get the legend for the form in front of you.

Abbreviations add a second layer. The Joint Commission's Do Not Use list bans U for units, IU, Q.D., Q.O.D., trailing zeros ("1.0 mg") and missing leading zeros (".5 mg"), and MS, MSO4 and MgSO4 for morphine and magnesium sulfate. You will still see them on older paper MARs. Our guide to medical abbreviations for legal professionals covers how to read them without guessing.

No federal regulation prescribes a MAR form. The rules set what the record must contain and how drugs must be given, and CMS surveyors read the MAR to check both. For a hospital that takes Medicare, the starting point is the medical records Condition of Participation:

"All practitioners' orders, nursing notes, reports of treatment, medication records, radiology, and laboratory reports, and vital signs and other information necessary to monitor the patient's condition."

The same section requires every entry to be "legible, complete, dated, timed, and authenticated" by the person responsible (482.24(c)(1)). On a MAR that means each dose has a date, a real time and a signature or initials that can be tied to a person. CMS surveyor guidance adds the point that matters most in litigation: "Documentation is expected to occur after actual administration of the medication to the patient." A dose charted at 08:00 for a patient who was in radiology until 08:50 is a documentation problem, whatever happened to the drug.

The 5 rights and the 5 stages

CMS expects hospital policy to require 5 checks before every dose, the "5 rights": right patient, right medication, right dose, right route, right time. The same guidance reminds surveyors that the 5 rights cover only administration. Errors start earlier, and the MAR sits in the middle of a 5-stage process:

A clean MAR can hide a prescribing error, and a messy MAR can sit on top of care that was fine. That is why a reviewer reads the order, the MAR and the monitoring together.

There is no single federal deadline for every dose. The CMS surveyor guidance for 482.23(c) sets 3 windows. Each hospital decides which drugs fall in which window, so the policy is the first document to request.

CMS lists examples of drugs a hospital may treat as time-critical: antibiotics, anticoagulants, insulin, anticonvulsants, immunosuppressive agents, non-IV pain medication, drugs ordered within a set time of the order, drugs that must be spaced from other drugs, and anything ordered more often than every 4 hours. The list is illustrative. A drug can be time-critical for 1 patient and not for another, and the policy must say how nurses know which is which.

Missed and late doses

The same guidance requires a policy on doses that fall outside their window: a patient off the unit for a test, a refusal, a patient who cannot swallow, a drug that was not available. The policy sets when a nurse may reschedule on their own judgment and when the prescriber must be told first. A late dose with no reason code and no note is the entry that draws the most questions, because the policy almost always required one of the two.

PRN entries

An as-needed dose has 3 parts, and the MAR often records only 1. The reason (pain 5, agitation, nausea) has to match the order's indication and range. The time has to respect the minimum interval ("every 4 hours"). The effect, a reassessment after the dose, is usually required by policy within a set time and is the field most often left blank. In nursing homes, PRN psychotropic orders run out after 14 days unless the prescriber documents a rationale and a duration, and PRN antipsychotics cannot be renewed without a new evaluation (42 CFR 483.45(e)(4) and (5)).

Held doses and hold parameters

Orders for blood pressure drugs, heart rate drugs, insulin and anticoagulants often carry a parameter: hold for heart rate under 60, hold for glucose under 70. A correct entry shows the value that was checked, and the vitals flowsheet should show the same value at about the same time. A dose charted as given when the flowsheet shows a value below the hold line is one of the most common findings in a MAR review.

The clearest federal definition of a medication error comes from the nursing home survey guidance for tags F759 and F760 in Appendix PP. An error is a preparation or administration of a drug that departs from 1 of 3 things: the prescriber's order; the manufacturer's specifications (not recommendations); or accepted professional standards. A significant error is one that causes the resident discomfort or puts their health and safety at risk.

Surveyors mostly find errors by watching a medication pass, then comparing what they saw with the MAR and the orders. The guidance also lets them find errors in the record itself, including "discrepancies in the MAR that lead to identification of a medication error", with interviews and other documents to back it up.

The error rate calculation

The nursing home rule at 42 CFR 483.45(f) requires an error rate under 5% and no significant errors at all. The surveyor's formula is simple:

2 rules decide close cases. A rate below 5% cannot be rounded up, so 4.6% stays under the line. And any significant error is cited under F760 whatever the overall rate, so 1 missed dose of a heart drug can be a citation on its own.

What makes an error significant

The guidance gives 3 tests: the resident's condition, the drug category, and how often the error happened. Drugs with a narrow therapeutic index, where the effective dose sits close to the toxic dose, raise the stakes; the guidance names phenytoin, carbamazepine, warfarin, digoxin, theophylline and lithium. Its examples show the range. An omitted daily dose of metoprolol succinate is listed as significant; a missed multivitamin is not. Losartan due at 08:00 and given at 09:30 is listed as not significant; 2 oxycodone tablets due 20 minutes before a painful treatment and given after it are significant.

What each flag means

1. Metoprolol given at a heart rate of 56. The order says hold under 60. The MAR carries no heart rate, and the flowsheet shows 56 at 09:02. A recheck that was never charted is possible. On paper this is a parameter breach.
2. Ceftriaxone 74 minutes late. Outside a 30-minute window if the policy lists IV antibiotics as time-critical, which this one does. The note explains the delay: the IV failed and was restarted. The remaining question is whether the policy required the prescriber to be told.
3. 4 units instead of 6. The scale on the order and the glucose value do not match the dose charted. The next glucose value tells you whether it mattered.
4. PRN opioid with no reassessment. The reason was outside the order's range (pain 7 against an order for 4 to 6) and no reassessment was charted within 60 minutes.
5. Blank 16:30 insulin cell. The patient was NPO, so holding the dose may have been right. The MAR should say so with a code; a blank is not a code.
6. Cabinet removal with no MAR entry. Oxycodone left the cabinet at 18:05 under RN-B's login, and nothing on the MAR or in the waste record accounts for it. This is the entry most likely to draw a follow-up.

The same day on 1 timeline

The method below works on paper and electronic MARs, in hospitals and in nursing homes. It is slow by hand on a long stay, which is why the order of steps matters: build the list of doses that should exist before you read the doses that do.

1. Collect the full set. Every MAR page for the date range, the signed orders, the pharmacy profile, the vitals flowsheet, the glucose log, the nursing notes, and for controlled substances the cabinet removal and waste reports.
2. Build the dose skeleton from the orders. For each order, list every dose due between its start and stop, using the facility's standard times.
3. Match every MAR entry to a due dose. Mark each as given, held with a code, refused, or blank. Mark any entry with no matching order.
4. Check timing against the policy. Only after you know which drugs the policy lists as time-critical.
5. Check parameters and scales. Heart rate and blood pressure against hold lines, glucose against the sliding scale.
6. Check PRN entries. Reason inside the ordered range, interval respected, effect charted.
7. Reconcile controlled substances. Every cabinet removal should match a MAR entry, a waste record or a return.
8. Log each question with a page. 1 line per due dose, not per blank, so the log can be checked against the file.

A blank or late entry: the decision path

MAR REVIEW LOG
Patient: [ID]    Facility: [NAME]    Dates reviewed: [FROM] to [TO]
Policy used for timing: [POLICY NO., REVISION DATE]

Date | Due | Order (drug, dose, route, frequency) | Order page
     | MAR entry (given / code / blank) | Actual time | Initials
     | Parameter or scale value at the time | Source page
     | Other record covering the dose | Source page
     | Question | Category (omission, timing, dose, parameter,
       PRN, controlled substance, unauthorized)

Example:
03/03 | 09:00 | Metoprolol 25 mg PO q12h, hold HR under 60 | p. 44
      | Given | 09:10 | RN-B
      | HR 56 at 09:02 | p. 60
      | None | n/a
      | Given below hold parameter; recheck not charted | parameter

MEDICATION ADMINISTRATION RECORD
Name: ____________  Date of birth: ________  Record no.: ________
Allergies: ______________________  Weight: ______  Month: ______

Medication, dose, route, frequency: ___________________________
Hold parameters: ____________  Start: ______  Stop: ______
Prescriber: ____________  Verified by pharmacy: ______

Time | Day 1 | Day 2 | Day 3 | Day 4 | Day 5 | Day 6 | Day 7
_____|_______|_______|_______|_______|_______|_______|______
_____|_______|_______|_______|_______|_______|_______|______
_____|_______|_______|_______|_______|_______|_______|______

PRN DOSES
Date | Time | Medication and dose | Reason (score) | Initials
     | Effect | Time rechecked | Initials

CODES (edit to match policy)
H = held (write the value)   R = refused   N = NPO
O = off unit (write where)   NA = not available from pharmacy

SIGNATURES
Initials | Full name | Credential | Signature

MEDICATION RECORDS FOR [PATIENT], [DATES]
1. Every medication administration record page, paper or
   electronic, including PRN and one-time dose sections.
2. The code legend and signature legend for each MAR form.
3. All medication orders, with order history showing entry,
   verification, modification and discontinuation times.
4. The pharmacy medication profile.
5. Bar-code scan records for each dose, including overrides
   and the reason entered for each override.
6. Automated dispensing cabinet removal, return and waste
   reports for the patient.
7. Vital signs, glucose and pain score records.
8. Policies in force on the dates of care on medication
   administration timing, time-critical medications,
   missed and late doses, PRN reassessment and
   controlled-substance waste.
9. Any medication error or adverse drug event report for
   the patient, to the extent not privileged under
   [STATE STATUTE].

Before you rely on a MAR printout

• Every page for every day is presentCount pages against the date range, including PRN and one-time sections.
• Code and signature legends are in handWithout them, codes and initials are guesses.
• The timing policy for those dates is in handThe revision in force on the date of care, not today's.
• Orders include their historyStart, change and stop times, plus the current list.
• Scan and cabinet data requestedThey time-stamp the dose from a second system.
• Hand-corrected entries flaggedStrike-throughs, late entries and addenda get their own line in the log.

0 of 6 checked.

When a MAR looks edited after the fact, the method changes. Our guides on altered medical records and charting by exception cover late entries and blank cells in more depth.

Most hospital MARs are now electronic, and many are tied to bar-code scanning. The best-known evidence that this reduces errors comes from a study at an academic medical center that compared units before and after bar-code eMAR. Poon and colleagues observed thousands of administrations directly and found a clear drop in errors other than timing errors.

For a reviewer, the eMAR changes what exists. Paper MARs give you initials and a handwritten time. An eMAR has a second layer behind the printout: scan times, override reasons, the order version on screen, and who charted when. The printout rarely shows it, so ask for it by name, as the request list in chapter 7 does.

Where AI helps with a MAR

A long stay produces hundreds of MAR pages, and the review in chapter 7 is mostly matching: this dose against that order, this time against that vital sign. That is the part AI medical record review does well. A grounded system can pull every dose into a table, place each one on a timeline with the vitals, glucose values and notes, and give every line a page-level citation back to the source, which is what turns a MAR into an AI medical chronology you can check.

It has limits you should plan for. Scanned paper MARs need OCR, and initials in tiny grid cells are hard for any handwriting recognition model. A large language model (LLM) asked to summarize a MAR without citations may produce a fluent answer with a dose that is not on the page; hallucination is the reason every line has to point to its source. And no tool knows the facility's timing policy or legend unless you have them. The human in the loop decides what a flag means.

Medrecords AI works this way on the files you upload. It builds a cited medical chronology with every entry linked to its page, routes each page through OCR matched to its content, including handwritten entries, answers questions like "every metoprolol dose with the heart rate nearest to it" through cited Q&A, and flags records that should exist but were not produced. Flags are signals, not verdicts. It does not read eMAR scan logs or cabinet exports as data, it does not decide whether an entry is an error, and it does not retrieve records from providers. It runs under SOC 2 and HIPAA with a signed business associate agreement (see security and HIPAA). Self-Service bills 10 cents a deduplicated page, down to 5 cents at volume, duplicates free; Enterprise On-Prem is an annual license.

If you are comparing tools, our guide to medical record review covers what to ask any medical chronology software vendor. See how MAR review fits medication error cases, nursing home neglect and legal nurse consultant work.

What is a medication administration record?

The part of the chart where nurses record each dose as given, held, refused or missed, with the drug, dose, route, scheduled time, actual time and initials. Hospitals and nursing homes keep it as part of the medical record.

What is the difference between a MAR and an eMAR?

An eMAR is the electronic version inside the EHR. Orders flow into it from the prescriber and pharmacy, and it is often paired with bar-code scanning. It also stores scan times and overrides that a paper MAR cannot.

What should be on a MAR?

Patient identifiers and allergies; each order with drug, dose, route, frequency and any hold parameter; start and stop dates; scheduled times; an entry for every dose with time and initials or a code; PRN reasons and effects; and a signature legend.

What are the 5 rights of medication administration?

Right patient, right medication, right dose, right route and right time. CMS expects hospital policy to require all 5 to be confirmed before each dose. Some nursing texts list more, up to 9.

How late can a scheduled medication be given?

Under CMS hospital guidance, within 30 minutes either side for drugs the hospital lists as time-critical, 1 hour either side for drugs given more than daily up to every 4 hours, and 2 hours either side for daily, weekly or monthly doses. Facility policy decides the categories.

What does a blank cell on a MAR mean?

That nothing was charted. It may be an omitted dose, a dose given but not charted, or a held dose missing its code. Other records (notes, scan logs, cabinet reports) usually settle which.

How long do hospitals keep medication records?

At least 5 years under 42 CFR 482.24(b)(1), as part of the medical record. Many states require longer.

Can a patient get a copy of their MAR?

Yes. The MAR is part of the medical record, so it falls in the designated record set covered by the HIPAA right of access. The provider has 30 days to act, with 1 extension of up to 30 more days (45 CFR 164.524).

Can AI read a scanned or handwritten MAR?

It can extract most typed entries with OCR and many handwritten ones, but initials and times in small grid cells are where errors cluster. Use a tool that cites every value to its page and check the flagged cells by hand.

Can software find medication errors in a MAR?

Software can flag mismatches: a dose charted against a hold value, a dose outside the order's range, a due dose with no entry. Whether a mismatch is an error depends on the order, the policy and the clinical facts, which a person decides.

Is it HIPAA compliant to upload a MAR to an AI tool?

It can be, with a vendor that signs a business associate agreement, holds a SOC 2 report and commits in writing not to train on your data. A consumer chatbot without a BAA is a different matter.

Regulations were read in full text from primary sources in September 2026, and quoted text is verbatim. CMS surveyor guidance was read from the published transmittal and appendix. Study figures come from the published paper. The MAR sheet, patient, policy, times and pages in chapters 2, 6 and 7 are hypothetical. Product facts come from this site's product pages. Nothing here is legal or medical advice.

• 42 CFR 482.24(b)(1), (c)(1), (c)(4)(vi) and (c)(4)(viii): retention, entry standards, medication records, completion within 30 days.
• 42 CFR 482.23(c)(1) and (c)(5): drug administration and reporting of administration errors.
• 42 CFR 482.25(b)(5): automatic stop orders.
• 42 CFR 483.45(c), (d), (e) and (f): nursing home drug regimen review, unnecessary drugs, PRN psychotropic limits, error rate.
• CMS State Operations Manual Appendix A, Transmittal 151 (November 20, 2015): interpretive guidance for 482.23(c): the 5 rights, the 5 stages, timing windows, time-critical examples, missed doses, documentation after administration.
• CMS State Operations Manual Appendix PP, F759 and F760 (Rev. 173, 2017): medication error definitions, error rate formula, significance tests and examples.
• 45 CFR 164.524: HIPAA right of access, 30 days plus 1 extension.
• The Joint Commission, Do Not Use list of abbreviations.
• Poon et al., "Effect of bar-code technology on the safety of medication administration", New England Journal of Medicine 362(18), 2010: non-timing errors 11.5% without and 6.8% with bar-code eMAR, a 41.4% relative reduction.