Short answer. Yes. The Revised Penal Code punishes any physician or surgeon who, in connection with the practice of his profession, issues a false certificate. The offence is committed by the act of issuing it, and a private person who falsifies such a certificate is separately punished.
What the law says
Any physician or surgeon who, in connection with the practice of his profession, shall issue a false certificate
Revised Penal Code, Article 174 — False Certificates. Read the full provision →
What makes the certificate "false"
The falsity that matters is a statement of fact that is untrue — certifying an illness the patient never had, days of confinement that never happened, an examination that was never performed, or a fitness the doctor never assessed. A diagnosis that later proves wrong, honestly reached after a real examination, is a professional judgment, not a false certificate. The distinguishing feature is knowledge: the physician must have known the certificate did not reflect reality. Note that the certificate need not have been used yet, and no one need have suffered loss. The wrong lies in putting a professional's signature behind an untruth, because that signature is what everyone else relies on.
Three sets of offenders
The article covers a physician or surgeon who issues a false certificate in connection with the practice of his profession, and a public officer who issues a false certificate of merit or service, good conduct or similar circumstances. It then adds a third: any private person who falsifies a certificate falling within those classes faces arresto mayor. So the employee who edits the doctor's certificate before handing it to human resources, or who manufactures one outright, is inside this provision even though he is not a doctor. The person who merely asked for the favour may still face liability as a participant, depending on what he did.
The penalty, and the 2017 peso figures
For the physician and the public officer, the penalties are arresto mayor in its maximum period to prisión correccional in its minimum period, together with a fine not exceeding ₱200,000. That ₱200,000 is the current amount, set by Republic Act No. 10951 (2017), which revised the peso values and fines throughout the Revised Penal Code. Older reproductions still print the 1930 figure — ₱1,000 for this article — and relying on them will give a badly mistaken picture of the exposure. Check which version any source you are reading actually gives.
The consequences that hurt most
For a doctor, the criminal penalty is rarely the worst of it. Issuing a false certificate is professional misconduct, and the regulatory board that licenses physicians can suspend or revoke the licence in proceedings entirely separate from the criminal case. Where the certificate was used to obtain money, benefits or leave, estafa or falsification charges can be added, and an employer may treat its submission as a dismissible offence. This article does not, however, reach a certificate that is merely incomplete or badly worded, nor a genuine difference of medical opinion. If you have been asked to explain a certificate you signed or submitted, get counsel before responding in writing.