Can I contact graduate office regarding decision timeline (to know my application status)? I am an applicant of Graduate program in Biological sciences of X University, USA. My application deadline was Dec 15, 2015 and I submitted application with required documents on time (PhD application). For the past 4 months my application status in portal shows "In review". In the university website,no specific decision timeline is given. My question is can I contact through e-mail to graduate program coordinator to know the decision status? It is almost April 1st week, I fear my application might be rejected, but I want to know it from officials.

Is it normal to ask Graduate program coordinator to ask about decision timeline or my application status?

Thanks.
You will likely find out within the next few weeks. But asking them the date by which they'll let applicants know their decision status is a perfectly reasonable question. After all, you might have other offers that may require a time-sensitive answer.

I don't know if I'd ask directly about your application status, but asking for their review timeline is perfectly reasonable and appropriate.