1:18 PM PT -- Matthew Binninger, Dr. Mark Chavez’s attorney, tells TMZ … Mark has accepted responsibility for his actions by entering his guilty plea, he is cooperating with the government, and he has begun the process to surrender his medical license.

“The factual basis from the plea agreement will be used as the basis for the medical board to issue a complaint against him, requesting the surrender of his license. We will agree with that conclusion, and at that point, his license will be revoked. I cannot give you an exact timeline about when that will happen because it is up to the medical board, but the wheels are in motion, and now that the guilty plea has been entered it should happen sooner than later.”

One of the doctors charged in connection with Matthew Perry's ketamine death is one step closer to prison ... because he just copped to a crime.

Dr. Mark Chavez, one of 2 physicians busted in the Perry case, appeared before a judge in federal court Wednesday in Los Angeles and pled guilty to one count of conspiracy to distribute ketamine.

As we reported ... Chavez quickly cut a deal with the feds after a slew of arrests were made in connection with Perry's death. Now, he's formally entered his plea.

Chavez is facing up to 10 years in prison, but his sentencing won't happen until next April.

In the meantime, Chavez remains free on a $50,000 bond ... and he's already surrendered his passport, and agreed not to work as a doctor.

He's reportedly surrendered his medical license. According to the feds, Chavez was on the receiving end of an email from one of the other charged suspects, Dr. Salvador Plasencia, which read, "I wonder how much this moron will pay [for the ketamine].

Dr. Chavez is one of 3 who took plea deals in Matthew's case ... joining Perry's assistant, Kenneth Iwamasa, and Erik Fleming, who prosecutors say helped broker the drug deals.

Meanwhile, the other two charged in the case ... Dr. Plasencia and Jasveen Sangha, AKA "The Ketamine Queen," ... are fighting their charges, and have each pled not guilty.