How to tell your employer you are taking medical leave
A medical leave request is the written notice you give your employer that you will be away from work for health reasons, and when you expect to return. It is not the same thing as the medical certificate itself: the certificate proves you are unfit for work, the letter tells your employer what that means for them — dates, handover, how to reach you, and which entitlement you are relying on.
Employers rarely dispute the illness. What causes problems is silence, vague dates, and leave that is taken without ever being classified — which is what turns a legitimate absence into a disciplinary conversation months later.
Notify first, document second
Almost every system, and almost every contract, separates the two obligations. You must tell your employer as soon as reasonably practicable — usually the first morning of absence, by whatever method your contract specifies — and you must provide evidence within a set window. Missing the first deadline is what gets people in trouble; missing the second is usually fixable.
Send the letter even if you have already phoned. A dated written notice is what protects you if the absence is questioned later, and it gives HR something to file.
United States: FMLA, and what it does not cover
The Family and Medical Leave Act gives eligible employees up to 12 weeks of unpaid, job-protected leave in a 12-month period for a serious health condition, or to care for a spouse, child or parent with one. You qualify if you have worked for the employer for at least 12 months and at least 1,250 hours in the previous year, at a site with 50 or more employees within 75 miles.
- Give 30 days' notice when the need is foreseeable — planned surgery, a scheduled procedure. Otherwise, notify as soon as practicable.
- Your employer may require certification from a health care provider, and may ask for recertification periodically.
- FMLA is unpaid. Paid leave comes from your employer's own policy, from accrued sick time, from short-term disability insurance, or from a state programme — several states run their own paid family and medical leave schemes with broader eligibility than FMLA.
- If your condition is a disability, the Americans with Disabilities Act may separately require reasonable accommodation, including leave, even when FMLA does not apply.
United Kingdom: self-certification then a fit note
For the first 7 calendar days you self-certify — no doctor's note is needed, and employers cannot lawfully insist on one. From the eighth day you need a fit note from a GP or other eligible healthcare professional, which may say you are unfit for work or that you may be fit subject to adjustments such as altered hours or amended duties.
Statutory Sick Pay is paid by your employer for up to 28 weeks at a flat weekly rate set each April, subject to a minimum earnings threshold. Many contracts provide company sick pay on top; check your handbook, because the notification deadlines in it are usually stricter than the statutory ones.
What the letter should contain
- The first day of absence and your expected return date, or a clear statement that the duration is not yet known.
- The type of leave you are requesting — sickness, injury, surgery, maternity, paternity, caring for a family member — because the entitlement and the paperwork differ.
- Confirmation that medical evidence is attached or will follow, and by when.
- A short handover: what is urgent, who can cover it, where the files are. This is the part employers actually read, and it is the cheapest goodwill you will ever buy.
- How and when you are willing to be contacted. You are not obliged to be available while on medical leave; saying so politely and in advance prevents awkwardness.
Mental health is medical leave
Burnout, anxiety and depression are health conditions, and leave for them follows the same route as leave for a physical illness. You are not required to disclose a diagnosis to your employer — a certificate stating you are unfit for work is sufficient, and in most systems the employer is not entitled to the underlying details. Keep the letter factual and short.
Before you send it
Read your contract's absence clause first: it will name the person to notify, the deadline, and the evidence required, and those contractual terms are usually tighter than the statutory floor. Send the letter to HR rather than only to your manager, keep a copy with proof of sending, and if the leave extends, send a short update rather than letting the original return date pass in silence.