The tuberculosis test comes with a three-month deadline that is easy to lose track of amid everything else a new permit holder is arranging. Discovering the window has already closed prompts an understandable panic about whether the residence permit itself is now at risk.
Get to a GGD (municipal health service) this week and book it — don't wait for a letter first. When your residence permit was issued, you signed a declaration agreeing to complete a TB test within three months of receiving it (this only applies if you're from a country the IND flags for this; EU/EEA nationals, Americans, Canadians, Australians, and several others are exempt, so check whether it even applied to you). Missing the window doesn't trigger automatic withdrawal, but it does put you technically in breach of the condition your permit was granted under, and if it surfaces later — during a renewal check, say — the IND can use it as grounds to withdraw the permit. Showing up late and getting tested beats doing nothing every time: bring the referral form that came with your permit to the GGD, they'll test you and send the result straight to the IND. If it's been a while and you're anxious about it, calling the IND directly to explain tends to go over better than staying quiet and hoping it goes unnoticed.